Cleaning a drive of unwanted data is quite a complicated task because Windows has many places where it keeps records of user activity (registry, file slack, MRU lists, swap file, dump file, etc, etc).
There are a wide number of tools available, some better than others. When evaluating these products I always suggest that you run Recover My Files (
www.recovermyfiles.com) afterwards to see what comes back. However, having said this, Recover My Files is a data recovery tool and is not necessarily concerned about checking for such things a left over file names in run lists. The only true way to determine how well the program works its to use Computer Forensics software to do a thorough review of what information is left.
Personally, I use Secure Clean, from
www.wipemyfiles.com.
Its much easier to wipe an entire drive, as this is the simpler process of writing 0's from begining to end. A program to do this is Wipe Drive from
www.wipemyfiles.com.