The Reg.exe utility does not compress a registry key when the utility saves a registry key to a hive file on a computer that is running Windows Server 2008 or Windows Vista
Consider the following scenario:
- You try to make copies of the registry or of the registry keys on a computer that is running Windows Server 2008 or Windows Vista.
- You use the reg save command to export the registry key into a hive file.
In this scenario, the reg save command does not compress the registry key during the exporting process. Therefore, the size of the hive file may be larger than expected.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB973817.