You don't have to reinstall Windows, just do a sysprep.
Go to C:\Windows\System32\Sysprep and open sysprep.exe then select OOBE, check 'generalize' set reboot in shutdown options and confirm with OK. You'll keep all the programs and your machine will be wiped clean of drivers.
Edit: Forgot to mention, if you want to keep your user account with all the personal settings etc, use the built-in Windows Easy Transfer tool.
FYI, Sysprep doesn't delete user accounts unless you specifically tell it to do so.
Also, he upgraded his o/s from 32-bit to 64-bit so none of that would work anyhow.