I dunno. Malewarebytes is excellent but perhaps it doesn't have a definition yet for your friend's problem.
As a secondary opinion, you could possibly try scanning with Spybot Search & Destroy, XoftSpySE and/or HijackThis.
If those report clean as well, then I doubt there is an infection, but still possible.
Hopefully he did not try to use any patching software on the 7 install. Did he?
Have you checked the event viewer under windows logs?
Also, here is an excellent online scanner for single files, which uses multiple engines: Jotti's malware scan
Finally, from an elevated command prompt, do this command: