1. Please download and install the Windows Installer Cleanup Utility msicuu2. To install it simply run msicuu2.exe.
2. Once it is installed go to Start>All Programs>Windows Install Clean Up
3. Scroll through the options and highlight Microsoft Windows Server Update Services 3.0
4. Click remove
5. Open a command prompt and run the following commands:
net stop wsusservice
net stop wsuscertserver
sc delete wsusservice
sc delete wsuscertserver
6. When complete, go back to the Windows Installer Cleanup Utility and highlight Windows Internal Database (MICROSOFT##SSEE) and click remove.
7. Go back to the command line and run the following commands
net stop mssql$microsoft##ssee
sc delete mssql$microsoft##ssee
8. Delete or edit the associated reg keys as noted below:
a. Go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server and edit the “InstalledInstances” value and remove “MICROSOFT##SSEE”
b. Remove the “MICROSOFT##SSEE” subkey under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server
c. Remove the “MSSQL.2005” subkey under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server
d. Rename the following folder:
\%Windir%\SYSMSI\SSEE\MSSQL.2005\MSSQL\Data
to
\%Windir%\SYSMSI\SSEE\MSSQL.2005\MSSQL\Data.old
At the completion of this you should be at a point where you can reinstall WSUS from scratch if you like.