Umm, why not just reformat, and reinstall the O/S and driver/app disk? probably wont take more than 45 min. or so
There is no telling what the store (or a customer playing with it) installed/deleted etc.
The fix is as easy as placing the dvd in drive, restarting computer>hitting any key at prompt to boot from disk>following prompts/deleting existing partition/reinstall Vista
or booting from recovery partition and doing a full destructive reformat/reinstall if no media disk is available.