If you receiving error like….
"Unable to downgrade data from version 13,0,0,0 to 12,4,0,0'
Process: GROOVE.EXE (ID:5652 (0x00001614))
Thread ID: 5212 (0x0000145c)
Date: Thursday, July 13,2010 8:20:10 PM"
Simply follow the steps below.
Start -> Run and type "regedit"
Locate for "HKEY_CURRENT_USER / Software / Microsoft / Office" and delete the folder "14" (Denotes the version of Office 2010)
Just delete that entire folder ("Groove"). The names may be slightly different, like "AppData."
C:\Documents and Settings\<windows user>\Local Settings\Application
Note: The folder "Local Settings" may hidden you should enable the hidden folder view to find the above folder. Restart not required