Please help! Windows 7 won't load on this laptop (factory reset doesn't help)

I've been passed a laptop to sort out, which was full of malware, Windows (7) running slowly and occasionally crashing, the usual state of a machine used by someone clueless and apathetic about computer security. I was told I could just reformat it, as he doesn't want anything off it saving, so I tried resetting it to the factory default, which seemed to work, but when Windows booted up, it just stuck in the Windows 7 loading screen (black screen, with the four colour flag thing).

I tried safe mode, but it also crashes/gets stuck whilst loading - the last file it lists in the loading screen is

WINDOWS\SYSTEM32\DRIVERS\CLASSPNP.SYS

I retried factory reset, with the same results, so I tried to install Windows 7 on to the laptop from my Windows 7 DVD, in case the factory reset image on the laptop had somehow gotten corrupt, but again Windows locks up (or goes into an infinite wait state, whatever it is), and now I can't even access factory reset, as the (non-working) install on the laptop didn't add the option, of course.

I've tested the physical memory (MEMTEST86+) and the hard drive, and they both give no errors, and I've reset the BIOS to it's original settings (a million to one chance that that was the fault, but I tried anyway), so can anyone suggest anything, please?

The laptop is a Samsung np305e5a-a03uk, Windows 7 64-bit, AMD A6 3420M CPU, 6GB RAM.

 

Nevermind, the owner said he'd buy a new laptop, so I've given this one back to him.