On my Windows 7 Ultimate x64 I can't do anything with the existing instance of MS SQL Server 2008 R2. It was my mistake to uninstall some components related to SQL Server before running the main uninstaller.
Now the uninstaller seems like doing its job and reporting "All done", but in the end nothing happens, "\Program Files\Microsoft SQL Server" folder still has 700 Mb of content. Reboot has no effect.
How to remove SQL Server 2008 R2 manually?
Rerun the SQL Server 2008 R2 setup and use Remove option. It it does'n work I suggest tp try the Repair option and then again Remove
To uninstall SQL Server 2008 R2 we have 2 options by using control panel or from SQL Server setup and click on remove and select all features and uninstall.