Acronis has a strong product base but beyond that I'm no familiar with that program.
What you need to do is after you run any of those cleaner programs is get into your advanced search and starting looking at stuff like *.doc and *.pdf, etc. Make sure you make all files and folders viewable.
Look at your program files and get rid of backups and files for stuff like MS Money. Just spend some time poking around in your drive. search for your name and ssn and anything you can think of that u use you dont want out*.avi?
The free program Ccleaner will do a good job of cleaning out your history, cookies and that type of viewable data.
Then run a wipe program on unused drive space.
I don't know your sit, where this lappy is going but if it is back to gateway I doubt they will fish, but no telling who will end up with that drive.
Even reinstalling/formating out windows will not kill all traces of what is/was on that drive but surely is safest bet. Best is do the reinstall and then run a good wipe on unused space.
Edit: Dont forget to wipe your restore points if using. What if you wipe all that stuff and someone just does a system restore?