%systemdrive% is defined as the disk drive that contains the Windows directory. There are various reasons why you may want to relocate the Users directory or the ProgramData directory to other disk drives.
For Windows Vista, the most common reasons are as follows:
- It is easier to back up data from a single drive and from a drive that contains only user files.
- It is easier to rebuild the operating system disk drive on a user’s computer if user data is located on a separate volume. In this case, the drive that contains the Windows directory can be formatted, and Windows can be reinstalled without having to worry about how to remove user data.
For Windows Server 2008, the most common reason is as follows:
- There are performance improvements when you relocate the Users directory and the ProgramData directory to a disk drive other than the operating system disk drive.
For more information, click the following article number to view the article in the Microsoft Knowledge Base:
929831 (http://support.microsoft.com/kb/929831/ ) A description of known issues with the FolderLocation settings in the Windows Vista Unattend.xml file
Note If you use the FolderLocations unattend setting to move user data to a location other than the %systemdrive% disk drive, some servicing components may not be installed. Some components may include critical updates, security updates, hotfixes, and service packs. This is not an issue if you have installed the servicing stack update for Windows Vista Service Pack 1 (SP1). This update is described in Microsoft Knowledge Base article 937287. When you install update 937287, critical updates, security updates, hofixes, and service packs are installed if the Users directory and the ProgramData directory are located on a disk drive other than the disk drive that contains the Windows directory. Update 937287 is also included in Windows Server 2008. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
937287 (http://support.microsoft.com/kb/937287/ ) A software update is available for the Windows Vista installation software feature
Information that is documented in the current release of the Windows AIK and the Windows OPK
The Windows Automated Installation Kit (AIK) and the Windows OEM Preinstallation Kit (OPK) for Windows Vista SP1 and for Windows Server 2008 contain documentation warnings that are related to the usage of the ProfileDirectory and ProgramData unattend settings. These are the settings that let you relocate the Users directory and the ProgramData directory to locations other than their default locations. This includes other disk drives.
These warnings were included before the servicing stack update (update 937287) was available. This update addresses the issue that is discussed in the warning text. Windows AIK and the Windows OPK documentation reads as follows. The Important notes no longer apply. The Caution notes still apply.
Setting information from the Windows AIK and Windows OPK documentation
ProfilesDirectory
The ProfilesDirectory setting specifies the path to the user profile folder.
Use this setting to move the user profile folder (typically %SYSTEMDRIVE%Users) to another location during Setup or Sysprep. The destination path can be on a volume other than the system drive, as long as it meets the following requirements:
It must be on an NTFS volume.
It must not be the path of another operating system user profile folder.
It must not contain any serviceable components.
This setting can be used to keep system data separate from user data. If Windows is re-installed on the system volume, a user with administrative rights can manually recover data from this location.
Important:
These settings should be used only in a test environment. By changing the default location of the user profile directories or program data folders to a volume other than the System volume, you will not be able to service your Windows installation. Any updates, fixes, or service packs will fail to be applied to the installation. Microsoft does not recommend that you change the location of the user profile directories or program data folders.
Caution:
Using ProfilesDirectory to redirect folders to a drive other than the system volume blocks upgrades. Using ProfilesDirectory to point to a directory that is not the system volume will block SKU upgrades and upgrades to future versions of Windows. For example if you use Windows Vista Home Premium with ProfilesDirectory set to D:, you will not be able to upgrade to Windows Vista Ultimate or to the next version of Windows. The servicing stack does not handle cross-volume transactions, and it blocks upgrades.
ProgramData
The ProgramData setting specifies the path to the program data folder.
Important:
These settings should be used only in a test environment. By changing the default location of the user profile directories or program data folders to a volume other than the System volume, you will not be able to service your Windows installation. Any updates, fixes, or service packs will fail to be applied to the installation. Microsoft does not recommend that you change the location of the user profile directories or program data folders.
Caution:
Using the ProgramData setting to redirect folders to a drive other than the system volume blocks upgrades.
Note If you use the unattend settings to set up the operating systems that are listed in this article, we will provide commercially reasonable efforts to support your scenario.
Reference: http://support.microsoft.com/kb/949977
