Upgrade to Windows versions that is before Windows 10 is blocked if Users and ProgramData directories are changed

Before Windows 10, using the ProgramData unattend setting to redirect folders to a drive other than the system volume will block your ability to upgrade to a later version of Windows that is earlier than Windows 10.

By changing the default location of the User directories or ProgramData folders to a volume other than the system volume, you cannot service your Windows installation. Any updates, fixes, or service packs cannot be applied to the installation. We recommend that you do not change the location of the user profile directories or program data folders.

Beginning with Windows 10, upgrades are supported even if user profiles are redirected to another drive. For example, if you are using Windows 8.1 with ProfilesDirectory set to D:\, you can still upgrade to Windows 10.

Original KB number:   949977

More information

%systemdrive% is defined as the 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 drives.

For Windows, 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 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.
  • The %systemdrive% does not have enough disk space.

For Windows Server, the most common reason is as follows:

  • There are performance improvements when you relocate the Users directory and the ProgramData directory to a drive other than the operating system drive.

For information about how to use the answer file setting, see Answer Files Overview.

Note

If you use the FolderLocations unattend setting to move user data to a location other than the %systemdrive% drive, some servicing components may not be installed. These components may include critical updates, security updates, hotfixes, and service packs.

Information that is documented in the Windows AIK and the Windows OPK

The Windows Automated Installation Kit (AIK) and the Windows OEM Preinstallation Kit (OPK) for Windows and Windows Server contain documentation warnings that are related to the usage of the ProfilesDirectory 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 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. You cannot upgrade such installations to the Windows version that is before Windows 10.

Reference

For more information, see FolderLocations.