[Can Malware hide in somebodys profile?]

Is it possible for malware/spyware or a virus to hid in somebodys profile? Have a friend who has his account and his wife has her account on XP Home all up to date. I ran MBAM while I was in his account and it didn't find anything. Also ran Spybot and nothing. AVG shows nothing either. Could something be in hers that wouldn't be seen doing the checks in his? I know that it shows scanning the C drive and I would think that it would scan EVERYTHING on the C including the other account.
Of course I don't really make enough an hour to think by myself.

 

The only real scenario I can see that would make it possible is if her account is a Limited Account, where her account would already be forbidden to perform system wide changes, so the malware either error's out or infects whatever it can do.
My two cents, sir.

 

I can maybe see that. Thing is they both have the same privileges. Just a different name to log into.