Or try this
1.Close Sage MAS 90 or 200.
2.Select from Windows Start / Run. In the 'Open' field, enter ""REGEDIT"" (without quotes) and click 'OK'.
3.From the Registry Editor, select HKEY_CURRENT_USER / Software / Sage / Sage MAS 90 Business Desktop sub tree.
4.Right-click the 'Sage MAS 90 Business Desktop' sub key and click the 'Delete' button.
5.Close the Registry Editor and restart Sage MAS 90 or 200.
Keys may vary slightly depending on the version