Wiping Personal Data

I do some volunteer work for a thrift shop and they get quite a few donated computers. Obviously the donors are concerned about their data, and most don't even remotely know how to clear it. Since there can be numerous, I don't have the time to rebuild each machine the right way. Does anyone have a script that could create a new user profile, and delete all the old ones? Or a program that would wipe all the user folders? I'm not terribly concerned about the DoD wipe since they make sure donors know there are no guarantees on data safety.

 

You can use CCleaner. Select 1, 3, 7 or 35(!) passes. 3 is good enough for home PCs.
Open CCleaner > Options > Settings and select the number of passes.
Then click Include > Add and navigate to those folders.
Finally click Cleaner > Analyze > Run Cleaner.

http://www.majorgeeks.com/files/details/ccleaner_standard.html