How to Fix Userenv Errors in Windows XP

Remove Registry Key
1. Click on the Start menu and then select the 'Run' option. Type in 'regedit' into the text box and then click the 'OK' button. This will open the Windows Registry Editor.
2. Click the Edit drop-down and select the 'Find' option. Type in '{CF7639F3-ABA2-41DB-97F2-81E2C5DBFC5D}'
3. Right-click on the registry key with the 'Internet Explorer Machine Accelerators' data name and then select 'Delete' from the context menu.
4. Click the 'X' in the upper right corner of the window to close the Registry Editor.
Re-Register the Userenv.dll File
5. Click the Start button and then select the 'Run' option. Type in 'cmd' into the text box and then click the 'OK' button.
6. Type 'regsvr32 userenv.dll' and then press the 'Enter' key. Wait while Windows XP re-registers the file.
7. Click the 'X' in the upper right corner to close the window.