Doubt this is virus-related but can't think of any other reason why this would happen, anyway:

Switched the PC on this morning and as normal went on to my profile, usually, the first things that come up are AVG virus scanner and MSN. This morning they didn't, which I found slightly weird. So anyway, I tried to open (?) the start menu up and it wouldn't let me do that. I restarted the PC and tried this a few more times. Mentioned this to my dad who told me to go try his profile. For some reason, it worked - I was able to do what I wanted to do on his profile that I wasn't able to do on mine. So, stayed on his profile for a bit and then I shut the PC down. (As normal) Tried going on to mine again this evening (Just to see if there was a glitch on my profile which had gone) and still had the same problem. I got told by my brother to restart the PC and use safe mode. He ran the full AVG scan and found some infected files but am still unable to do anything on my profile. Why?