It's worth taking a backup of your D drive before removing and reinstalling all the programs, anyway. Then once you've reinstalled your programs, restore the backup. That way, things which depend on the registry in a fundamental way (i.e. they need some details in the registry to start) but don't store 'modifiable' data there, like settings files and saved game data, will be restored to the state they were in before your reinstall. I do this with my most-used programs every time I reinstall - it sometimes works between different OSs as well.