Backing Up Microsoft Outlook Offline Folder Files (.ost)

This guide helps fix an issue where Microsoft Outlook .ost files are not backed up because they are excluded from the VSS snapshot by default. However, it is easy to change as these settings are kept in the Windows registry.

Next Century
5 steps
10 seconds

Microsoft Outlook

In the Windows search, type regedit and select the Run as administrator to open the Windows registry

Find the VSS registry key. They are located on this path [[HKEY_LOCAL_MACHINE\\SYSTEM\\CurrentControlSet\\Control\\BackupRestore\\FilesNotToSnapshot]]

Right-click on the **OutlookOST** key and select **Delete**

Close the Windows registry and restart your computer

Run the backup plan again, then make sure \*.ost files are backed up

Backing Up Microsoft Outlook Offline Folder Files (.ost)

Next Century
5 steps
10 seconds

Microsoft Outlook

In the Windows search, type regedit and select the Run as administrator to open the Windows registry

Find the VSS registry key. They are located on this path [[HKEY_LOCAL_MACHINE\\SYSTEM\\CurrentControlSet\\Control\\BackupRestore\\FilesNotToSnapshot]]

Right-click on the **OutlookOST** key and select **Delete**

Close the Windows registry and restart your computer

Run the backup plan again, then make sure \*.ost files are backed up