Windows 2000 Backup May Leave Temporary (Regxxxxx) Files on the Computer

If you use Windows 2000 Backup (Ntbackup) to back up a Windows NT-based computer or Windows 2000-based computer over the network, temporary work files may be created on the remote computer with names similar to Regxxxxx (where xxxxx is a five-digit number).

After Windows 2000 Backup is finished, these temporary work files are not removed and over time may consume a significant amount of disk space because new files are created using different names each time you perform a remote backup.

If you are using Administrator or Backup Operator privileges to back up a computer over the network, Windows 2000 Backup creates a temporary work file for each registry file or user profile file that is in use. These temporary files are generally created one folder above the location of the file you are backing up. For example:

• All open registry files located in the %SystemRoot%\System32\Config folder are copied to the %SystemRoot%\System32\Regxxxxx files folder.
• All open User.dat files located in the Documents and Settings\UserName folder are copied to the Documents and Settings folder as a Regxxxxx file.
• All open Userclass.dat files located in the Documents and Settings\UserName\Local Settings\Application Data\Microsoft\Windows folder are copied to the Documents and Settings\UserName\Local Settings\Application Data\Microsoft folder as a Regxxxxx file.

NOTE: Windows NT keeps user profiles in the %SystemRoot%\Profiles folder, which is maintained during a Windows 2000 upgrade.

This behavior does not occur on computers running Microsoft Windows 95/98, even though Windows 2000 Backup does back up the registry files.

Because these are copies of active registry and profile files, Microsoft recommends using one of the following workarounds:

• Connect to the remote computer using a read-only share. This prevents the temporary files from being created, but the active registry and profile files are not backed up.
• Build a batch file to run Backup, and then use a del command to delete the temporary Reg0*.* files from the computer after Backup is finished.
• Use a user account that does not have Administrator or Backup Operator privileges to back up the remote computer. This bypasses backing up the registry and user profile files.

Microsoft has confirmed this to be a problem in Microsoft Windows 2000.

This behavior does not occur if you use Ntbackup.exe for Microsoft Windows NT 3.x or Microsoft Windows NT 4.0, because these versions do not support backing up remote computer registry files.