Windows 7: How to reset / initialize offline files database?

Symptoms:

On a Windows Vista-based or Windows 7-based client computer, you can still access offline files even though the file server is removed from the network. Additionally, you can delete the offline files and the temporary files in the Offline Files item in Control Panel.

Resolution

To resolve this problem, re-initialize the cache of offline files. To do this, follow these steps:

1. Click Start, type regedit in the Start Search box, and then press Enter.
   
   Note If you are prompted for an administrator password or for confirmation, type the password or click Continue.
2. Locate the following registry subkey, and then right-click it:
   HKEY_LOCAL_MACHINE\System\
   CurrentControlSet\Services\CSC
3. Point to New, and then click Key.
4. Type Parameters in the box.
5. Right-click Parameters, point to New, and then click DWORD (32-bit)Value.
6. Type FormatDatabase, and then press Enter.
7. Right-click FormatDatabase, and then click Modify.
8. In the Value data box, type 1, and then click OK.
9. Exit Registry Editor, and then restart the computer.

Or use the following command to fix the problem

reg add HKLM\SYSTEM\CurrentControlSet\services\CSC\Parameters /v FormatDatabase /t REG_DWORD /d 1

Credit: http://support.microsoft.com/kb/942974