This document contains information about upgrading to the Windows Server® 2008 operating system including how to upgrade, supported scenarios, frequently asked questions, and known issues about the upgrade process. In addition to this document, you should read Release Notes for Windows Server 2008 (http://go.microsoft.com/fwlink/?LinkId=99299), which contains information about all of the known issues about this product.
We recommend a clean installation of Windows Server 2008 whenever possible. For information about performing a clean installation, see Installing Windows Server 2008 (http://go.microsoft.com/fwlink/?LinkID=104824).
If you decide that you want to upgrade to Windows Server 2008 instead of using a clean installation, read this document to prepare for your upgrade.
We recommend a clean installation of Windows Server 2008 whenever possible. For information about performing a clean installation, see Installing Windows Server 2008 (http://go.microsoft.com/fwlink/?LinkID=104824).
If you decide that you want to upgrade to Windows Server 2008 instead of using a clean installation, read this document to prepare for your upgrade.
In this document
For information about known issues that you may experience while upgrading and solutions for these issues see Known Issues When Upgrading to Windows Server 2008 (http://go.microsoft.com/fwlink/?LinkId=110830).
Preinstallation information
This section contains information that you should review and steps that you should take before you upgrade to Windows Server 2008.
System requirements
The following are estimated system requirements for upgrading to Windows Server 2008. If your computer has less than the minimum requirements, you cannot install Windows Server 2008 correctly. Actual requirements vary based on your system configuration and the applications and features that you install.
Processor
Processor performance depends not only on the clock frequency of the processor, but also on the number of processor cores and the size of the processor cache. The following are the processor requirements for this product:
- Minimum: 1 GHz (for x86 processors) or 1.4 GHz (for x64 processors)
- Recommended: 2 GHz or faster
Note An Intel Itanium 2 processor is required for Windows Server 2008 for Itanium-Based Systems.
RAM
The following are the RAM requirements for this product:
- Minimum: 512 MB
- Recommended: 2 GB or more
- Maximum (32-bit systems): 4 GB (for Windows Server 2008 Standard) or 64 GB (for Windows Server 2008 Enterprise or Windows Server 2008 Datacenter)
- Maximum (64-bit systems): 32 GB (for Windows Server 2008 Standard) or 1 TB (for Windows Server 2008 Enterprise, Windows Server 2008 Datacenter), or 2 TB (for Windows Server 2008 for Itanium-Based Systems)
Disk space requirements
The following are the approximate disk space requirements for the system partition. Itanium-based and x64-based operating systems vary from these estimates. Additional disk space may be required if you install the system over a network. For more information, see the Microsoft Web site (http://go.microsoft.com/fwlink/?LinkId=99285).
- Minimum: 15 GB
- Recommended: 40 GB or more
| Note |
|---|
| Computers with more than 16 GB of RAM require more disk space for paging, hibernation, and dump files. |
Additional requirements
The following hardware is also required:
- DVD-ROM drive
- Super VGA (800 x 600) or higher-resolution monitor
- Keyboard and Microsoft® mouse (or other compatible pointing device)
Additional disk space requirements for Active Directory domain controllers
If your Active Directory database and log files are placed in any of the following directories, ensure that the volume has at least twice the space used by the database and that it has log files available before you install Windows Server 2008:
- %SystemRoot%
- %ProgramFiles%
- %SystemDrive%\Program Files
- %ProgramFiles(x86)%
- %SystemDrive%\build
- %SystemDrive%\InstalledRepository
- %ProfilesFolder%
- %ProgramData%
- %SystemDrive%\Documents and Settings
Before you start Setup
Before you upgrade to Windows Server 2008, do the following to prepare for the installation:
- Test your applications. You must test your line-of-business and non-Microsoft applications before you upgrade your production servers. For specific instructions on how to test your applications, see Application Considerations When Upgrading to Windows Server 2008 (http://go.microsoft.com/fwlink/?LinkId=110831).
- Ensure that all x64 kernel-mode software is signed. In the x64 version of Windows Server 2008, all kernel-mode software (including drivers) that runs on the computer must have a signature. If your applications use unsigned kernel-mode software (which is common in many firewall and antivirus programs), the upgrade may be blocked until you uninstall the application. If an application does not uninstall cleanly, it may continue to block the upgrade.
- Back up your servers. Your backup should include all the data and configuration information that is necessary for the computer to function. It is important to perform a backup of configuration information for servers, especially those that provide a network infrastructure, such as Dynamic Host Configuration Protocol (DHCP) servers. When you perform the backup, be sure to include the boot and system partitions and the system state data. Another way to back up configuration information is to create a backup set for Automated System Recovery.
- Be aware that you cannot uninstall Windows Server 2008. After the upgrade is complete, you cannot uninstall Windows Server 2008. However, if Setup fails during the upgrade, you can roll back to your previous operating system.
- Ensure that your applications are compatible. In the Setup Wizard, after you have selected the Upgrade option, you are presented with a dialog box that includes a link to application compatibility information. Be sure to follow the link and review the information about your installed applications before you proceed with the upgrade.
In addition, review the manufacturer’s Web site for your installed applications to:- Determine if the application is supported throughout the upgrade process to Windows Server 2008.
- Verify that the manufacturer supports the application on Windows Server 2008.
- Determine if the application is supported throughout the upgrade process to Windows Server 2008.
- Review the known issues. For information about specific upgrade issues, read Known Issues When Upgrading to Windows Server 2008 (http://go.microsoft.com/fwlink/?LinkId=110830).
Supported upgrade paths
The following table shows which operating systems can be upgraded to Windows Server 2008.
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| With the exception of Windows Server 2008 for Itanium-Based Systems, this table applies equally to 32-bit and x64-bit versions. However, cross-architecture upgrades (32-bit to x64-bit or the reverse) are not supported. |
| Operating System | Upgrade Options |
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Upgrading server roles
The following table contains information for upgrading server roles to Windows Server 2008. If you have any of these roles installed on your server, read the specified upgrade information for actions and recommendations that pertain to that role.
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| Active Directory Certificate Services (AD CS) | If you have certification authorities (CAs) in your organization, see Move a Certification Authority to a different computer (http://go.microsoft.com/fwlink/?LinkId=110934). |
| Active Directory Domain Services (AD DS) | For more information, see Upgrading Active Directory Domains to Windows Server 2008 AD DS Domains (http://go.microsoft.com/fwlink/?LinkID=89032). |
| Active Directory Federation Services (AD FS) | There are no known issues when upgrading AD FS from Windows Server 2003 R2 to AD FS in Windows Server 2008. For more information about new features in AD FS for Windows Server 2008, see What's New in AD FS in Windows Server 2008 (http://go.microsoft.com/fwlink/?LinkId=85684). |
| Active Directory Lightweight Directory Services (AD LDS) | For more information, see Appendix B: Upgrading from ADAM to AD LDS (http://go.microsoft.com/fwlink/?LinkId=110935). |
| Active Directory Rights Management Services (AD RMS) | See the RMS to AD RMS Migration and Upgrade Guide (http://technet.microsoft.com/en-us/library/cc754277(WS.10).aspx) |
| Application Server | You cannot migrate the Application Server role from Windows Server 2003 to Windows Server 2008. It was rebuilt for Windows Server 2008, and it includes default support for applications that are built with .NET Framework 3.0 components, such as Windows Communication Foundation (WCF), Windows Workflow Foundation (WF), and Windows Presentation Foundation (WPF). Application Server offers optional role services that activate features in Windows Server 2008 (such as Windows Process Activation Service (WAS) support for non-HTTP protocols, TCP Port Sharing, and support for IIS 7.0). If you upgrade your server to Windows Server 2008 from Windows Server 2003 or an earlier operating system, and you want to use the capabilities of the Application Server role, you must reinstall the Application Server role by using the Add Roles Wizard in Server Manager. If you configure Windows Server 2008 with the correct application services by using the Add Roles Wizard, your applications will work correctly after you move them from Windows Server 2003 to Windows Server 2008. For more information, see Frequently Asked Questions for Application Server (http://go.microsoft.com/fwlink/?LinkId=110936). |
| DHCP Server | This content is still under development. |
| DNS Server | In some instances, domain names that were not blocked in previous versions of Windows Server are blocked in Windows Server 2008. You may experience issues if you subsequently implement or remove the Intra-site Automatic Tunnel Addressing Protocol (ISATAP) or the Web Proxy Auto-Discovery Protocol (WSUAD). For more information, see DNS Server Global Query Block List (http://go.microsoft.com/fwlink/?LinkId=110937). |
| Fax Server | When you upgrade a fax server from Windows Server 2003 to Windows Server 2008, the Fax Server role is automatically installed in the upgrade. However, only certain settings are maintained during the upgrade:
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| File Services | The Wbadmin command replaces the Ntbackup command that was released with previous versions of Windows. You cannot recover backups that you created with Ntbackup by using Wbadmin. A version of Ntbackup is available as a download for Windows Server 2008 and Windows Vista users who want to recover backups that they created using Ntbackup. This version of Ntbackup enables you to perform recoveries of legacy backups only, and it cannot be used on computers running Windows Server 2008 or Windows Vista to create new backups. To download this version of Ntbackup, see http://go.microsoft.com/fwlink/?LinkId=82917. |
| Network Access Protection (NAP) | To enable NAP, you must upgrade the following Windows Server 2003 server roles and role services to the specified Windows Server 2008 server role or role service:
(http://go.microsoft.com/fwlink/?LinkID=111013). |
| Print Services | All existing printers and printer drivers are deleted when you upgrade to Windows Server 2008, so it is important to back up all printers before beginning the upgrade. To do so, use the Print Management MMC snap-in on a computer running Windows Vista or Windows Server 2008. For more information, see Migrate Print Services (http://go.microsoft.com/fwlink/?LinkId=110939). |
| Streaming Media Services | For more information, see Update the Windows Media Server Platform (http://go.microsoft.com/fwlink/?LinkId=110940). |
| Terminal Services | For more information, see the Terminal Services section later in this document. |
| UDDI Services | For more information, see:
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| Web Server | For more information, see:
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| Windows Deployment Services | For more information, see the Windows Deployment Role Step-by-Step Guide (http://go.microsoft.com/fwlink/?LinkId=84628). |
| WSUS | For more information, see Windows Server Update Services 3.0 SP2 Migration Guide (http://go.microsoft.com/fwlink/?LinkId=156772). |
Terminal Services
Upgrading a Windows Server 2003-based terminal server
There are no known issues with performing an upgrade of a Windows Server 2003 terminal server to the Windows Server 2008 operating system. All settings and configurations are maintained during the upgrade.
However, a terminal server running Windows Server 2008 can only communicate with a Terminal Services license server running Windows Server 2008, and the license server must have Windows Server 2008 Terminal Services client access licenses (TS CALs) installed.
However, a terminal server running Windows Server 2008 can only communicate with a Terminal Services license server running Windows Server 2008, and the license server must have Windows Server 2008 Terminal Services client access licenses (TS CALs) installed.
Upgrading a Windows Server 2003-based Terminal Services license server
There are no known issues with performing an upgrade of a Windows Server 2003 Terminal Services license server to the Windows Server 2008 operating system. All settings and configurations are maintained during the upgrade. After performing the upgrade, you need to activate the license server with the Microsoft Clearinghouse.
For more information about activating a license server running Windows Server 2008, see “Activate a Terminal Services license server” in the TS Licensing Manager Help in the Windows Server 2008 Technical Library (http://go.microsoft.com/fwlink/?linkid=101640).
A license server running Windows Server 2008 that has the appropriate Terminal Services client access licenses (TS CALs) installed can support terminal servers that run the following operating systems:
For more information about activating a license server running Windows Server 2008, see “Activate a Terminal Services license server” in the TS Licensing Manager Help in the Windows Server 2008 Technical Library (http://go.microsoft.com/fwlink/?linkid=101640).
A license server running Windows Server 2008 that has the appropriate Terminal Services client access licenses (TS CALs) installed can support terminal servers that run the following operating systems:
- Windows Server 2008
- Windows Server 2003 R2
- Windows Server 2003
- Windows 2000
| Note |
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| If you have made a backup of the TS Licensing database on the Windows Server 2003 license server, you should not attempt to restore that backup onto the license server after it has been upgraded to Windows Server 2008. If you attempt to restore it, any unissued TS CALs in the TS Licensing database are not restored, and you must call the Microsoft Clearinghouse to restore those unissued TS CALs. After you upgrade the license server to Windows Server 2008, you should make a new backup of the TS Licensing database. |
Upgrading a Windows Server 2003-based Terminal Services Session Directory server
If you upgrade a Windows Server 2003-based server that is running the Terminal Services Session Directory service to Windows Server 2008, the Terminal Services Session Broker (TS Session Broker) role service is automatically installed.
When you upgrade the server, the Terminal Services Session Directory database is not preserved. However, if the server name remains the same, the terminal servers that are configured to use that Terminal Services Session Directory server will rejoin the farm in TS Session Broker, and the database automatically rebuilds.
When you perform the upgrade, we recommend that no users access the terminal server farm until all terminal servers have rejoined the farm in TS Session Broker. If you do not wait for the database to rebuild, users may not be able to reconnect to existing sessions.
Although the rebuild process occurs automatically, you can force the terminal servers to rejoin the farm by reapplying TS Session settings in TS Session Broker (or apply Terminal Services Session Directory settings if the terminal servers are running Windows Server 2003). You can do this by using Terminal Services Configuration on each terminal server in the farm, by using Windows Management Instrumentation (WMI), or by reapplying Group Policy settings.
If you are running the Terminal Services Session Directory service on a server cluster, we recommend that you remove the Terminal Services Session Directory service resource from the cluster before you perform a server upgrade.
| Note |
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| In Windows Server 2008, the name of the Terminal Services Session Directory feature is changed to TS Session Broker. |
When you perform the upgrade, we recommend that no users access the terminal server farm until all terminal servers have rejoined the farm in TS Session Broker. If you do not wait for the database to rebuild, users may not be able to reconnect to existing sessions.
Although the rebuild process occurs automatically, you can force the terminal servers to rejoin the farm by reapplying TS Session settings in TS Session Broker (or apply Terminal Services Session Directory settings if the terminal servers are running Windows Server 2003). You can do this by using Terminal Services Configuration on each terminal server in the farm, by using Windows Management Instrumentation (WMI), or by reapplying Group Policy settings.
If you are running the Terminal Services Session Directory service on a server cluster, we recommend that you remove the Terminal Services Session Directory service resource from the cluster before you perform a server upgrade.
Upgrade limitations
Note the following limitations when you are upgrading to Windows Server 2008:
- You must have a Windows Server 2003 operating system with Service Pack 1 or a Windows Server 2003 operating system with Service Pack 2 installed to upgrade to Windows Server 2008.
- You cannot upgrade to a version of the operating system that has fewer features than the operating system you are currently running. For example, you can only upgrade Windows Server 2003 Datacenter Edition to Windows Server 2008 Datacenter Edition.
- The Windows Server 2003 for Itanium-based Systems operating systems and Windows Server 2003 Web Edition operating systems cannot be upgraded. If you have these editions, you must perform a clean install and migrate the data from these computers to the new operating system.
- Upgrading is supported from x86-based and x64-based computers, but cross-architecture upgrades are not supported. For example, you cannot upgrade from an x86-based computer to an x64-based computer, even if the server you are upgrading is x64-capable.
- Cross-language upgrades are not supported.
- You cannot upgrade the failover clusters from Windows Server 2003 to Windows Server 2008. Before upgrading, you must uninstall failover clustering. For more information, refer to article 935197 in the Microsoft Knowledge Base (http://go.microsoft.com/fwlink/?LinkId=110946).
- Upgrading from Windows Server 2003 to a Server Core installation of Windows Server 2008 is not supported.
Frequently asked questions about upgrading
What changes have been made from Windows Server 2003 to Windows Server 2008?
Windows Server 2008 includes features that have been updated from Windows Server 2003 and features that are unique to Windows Server 2008.
For more information about these changes, see Changes in Functionality from Windows Server 2003 with SP1 to Windows Server 2008 (http://go.microsoft.com/fwlink/?LinkId=110947).
Are there tools to help me prepare to upgrade to Windows Server 2008?
The following tools are available:
In addition, the following resources are also available:
What type of support is available during the upgrade process?
When you upgrade a Windows Server 2003 operating system to Windows Server 2008, Microsoft provides technical support for the following:
Windows delivered software is defined as any software or software component, role, or function that ships with Windows Server or is delivered to Windows Server through Windows Update. This includes Microsoft utilities and applications.
If you experience issues while upgrading to Windows Server 2008, Microsoft Customer Service and Support (CSS) will assist customers in restoring their upgraded Windows Server 2003 environment to a supported state, even if non-Windows software may be contributing to the issue.
Windows Server 2008 includes features that have been updated from Windows Server 2003 and features that are unique to Windows Server 2008.
For more information about these changes, see Changes in Functionality from Windows Server 2003 with SP1 to Windows Server 2008 (http://go.microsoft.com/fwlink/?LinkId=110947).
Are there tools to help me prepare to upgrade to Windows Server 2008?
The following tools are available:
| Tool | Description | ||
|---|---|---|---|
| Windows Server Catalog (http://go.microsoft.com/fwlink/?LinkID=80785) | Provides a comprehensive list of software and hardware that has passed testing for Windows Server 2003 and Windows Server 2008.
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| Microsoft Assessment and Planning (MAP) Solution Accelerator (http://go.microsoft.com/fwlink/?LinkId=110948) | Assesses and conducts an inventory to help plan your migration to Windows Server 2008. Includes hardware assessment, virtualization recommendations, and a software installation inventory for Windows Server 2008 migration.
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| Works with Windows Server 2008 Software (http://go.microsoft.com/fwlink/?LinkId=110964) | Determines application compatibility with Windows Server 2008. This tool is a highly-automated self-test (which lasts two-four hours). It is designed to streamline the time required to develop and test commercial and custom applications. Upon completion, you receive a detailed summary outlining the test results. Passing Works with Windows Server 2008 testing indicates that the application's results are:
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| Certified for Windows Server 2008 Software (http://go.microsoft.com/fwlink/?LinkId=110962) Certified for Windows Server 2008 Hardware (http://go.microsoft.com/fwlink/?LinkId=110961) | Test mission-critical, line-of-business applications and hardware devices and systems. This testing is for compliance with Microsoft best practices for security, availability, and reliability, and for Windows fundamentals. Use these tests after obtaining the results from the Works with Windows Server Software test. This testing requires three-five days. Applications and hardware that demonstrate this high standard receive the Certified for Windows Server 2008 logo and are listed in the Windows Server Catalog. |
| Resource | Description |
|---|---|
| Innovate on Windows Server portal (http://go.microsoft.com/fwlink/?LinkID=87625) | Provides the following:
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| Application Compatibility and Certification technical forum on MSDN (http://go.microsoft.com/fwlink/?LinkId=110951) | Technical forum that addresses application compatibility and software certification questions about Windows Server 2008. |
| MSDN Developer Center for Windows Server 2008 (http://go.microsoft.com/fwlink/?LinkId=110952) | Portal for application development and testing resources. |
| Migration forum on TechNet (http://go.microsoft.com/fwlink/?LinkId=110954) | Technical forum for best practices concerning the Windows Server 2008 migration process. |
When you upgrade a Windows Server 2003 operating system to Windows Server 2008, Microsoft provides technical support for the following:
- The operating system
- Windows-delivered software
- Microsoft applications
Windows delivered software is defined as any software or software component, role, or function that ships with Windows Server or is delivered to Windows Server through Windows Update. This includes Microsoft utilities and applications.
| Note |
|---|
| There may be scenarios in which a Windows Server component, role, or function does not support an upgrade. The Compatibility Report will list these scenarios during the Windows Server 2008 Setup. |
- If a backup of the operating system is available, CSS will follow disaster recovery processes to assist you in restoring your server environment to a pre-upgrade status. There is no guarantee that any data can be recovered.
- If a backup is unavailable, CSS will assist you in recovering to a supported state as quickly as possible. For example, CSS will assist in reinstalling Windows Server 2003 and in upgrading to Windows Server 2008.
