Have you encountered error 0x84B30002 when uninstalling MSSQL 2008 R2, preventing the uninstall from proceeding? I have. So far I have only encountered the issue with Express Edition, although rumor has it that the error can occur with other editions as well. The error message will be displayed in a pop-up as well as the summary.txt log file in the installation directory. Here is how to fix it: Launch the registry editor by typing regedit in the Run bar in the start menu. Navigate to the following registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\ After expanding uninstall, you will need to locate each key related to the SQL instance you are attempting to remove - if there is only one instance on the server, locate each key with the word SQL in the DisplayName field. Within each key, locate the GUID. It will look something like this: 234A1B2C-12AB-1AB2-B1C2-A12B345678C1 and be typically contained in either the ModifyPath or Uninstall