hi,

for sql server, never use the program files but use the SQL setup and pick add or remove futures from an existing installation.

don't use CCcleaner!

command prompt for uninstall sql instance with the setup

MyInstance = name of your instance, probably MSSQLSERVER if the default.

setup.exe /ACTION=uninstall /FEATURES=SQL /INSTANCENAME=MyInstance

Remove directories related to SQL Server from Program Files (including x86)

Remove references to those directories from the registry (manual).

Remove references in registry to your old instance.

But normally uninstall should do the trick.