1. Remove WSUS Role
2. Remove the Database WSUS was using (SUSDB.mdf and SUSDB_log.ldf).
   1. If you were using the Windows Internal Database (WID), specifically delete the SUSDB.mdf and SUSDB_log.ldf in C:\Windows\WID\Data (or C:\Windows\SYSMSI\SSEE\MSSQL.2005\MSSQL\Data for Server 2008/2008 R2)
      1. 1. If the WID was only used for WSUS, you should remove the WID feature in Server Manager to fully clean up the installation. When you do remove the WID Feature, make sure to remove the entire C:\Windows\WID folder too. Not sure if the WSUS
         2. If you’re using Server 2008 / Server 2008 R2, use the following PowerShell command from an Administrative PowerShell prompt to remove the WID if it was used ONLY for WSUS:

      if ($env:PROCESSOR_ARCHITECTURE -eq ‘x86’) { msiexec.exe /x {CEB5780F-1A70-44A9-850F-DE6C4F6AA8FB } callerid=ocsetup.exe }
      elseif ($env:PROCESSOR_ARCHITECTURE -eq ‘AMD64’) { msiexec.exe /x {BDD79957-5801-4A2D-B09E-852E7FA64D01} callerid=ocsetup.exe }

   2. If you were using a remote SQL Server instance, detach the database from the remote server and physically delete the SUSDB.mdf and SUSDB_log.ldf.
   3. If you were using a local SQL Server instance (Standard or Express [See why you should not use Express edition for WSUS]) detach the database from the local server instance and physically delete the SUSDB.mdf and SUSDB_log.ldf.
3. In IIS, remove the ‘WSUS Administration’ website and the ‘WsusPool’ Application Pool if they still exist.
4. Remove the WSUS Content folder wherever you had it previously installed (eg. C:\WSUS, or D:\WSUS)
5. Restart the server.

WSUS should now be completely gone from your system. Now you should be able to re-install the WSUS role, and if necessary, the Windows Internal Database (WID) role too.