I long, long ago stopped putting -anything- onto the C: drive that wasn't the OS. Before it was the need to reinstall windows at regular intervals, and the fact that most programs had no connection to the OS; with Vista and the 'Lets lock the directory tree to keep the idiots safe!' philosophy that M$ has adopted, there is even more reason to have at least one additional hard drive to put you apps and perishable data on. It makes sectional backups easier, keeps it in plain sight (not buried in the ridiculous folder structure win has adopted), and if the OS blows, you lose no data. At worst, you might have to reinstall the app over itself to reset the registry entries. But a lot of programs will -still- fire up just fine if they are on an separate drive.