various programs end abruptly

Heres my situation. Various programs, any and all crash at certain times and up comes the approximate window "Such & such a program encountered an error and must end now, click to send an error report or cancel "

Now its not the end of the world as it doesn't happen all the time or at crucial times. However most often it happens to IE. However it happens to other programs, won't let me burn CD's, Limewire crashes, same thing with media player.

Now this all happened after I got a virus from some ****. I downloaded AVG and fixed it. Comp is working good since then, except for the crash. Its a new laptop since xmas (xp media i think).

I don't want to do a complete system reboot (F10 - and it makes my comp brand new aka just like day 1 - as it didnt come with recovery disks F10 is built in way of going back to day 1) but will if necessary.

What are my other options? I have a 8GB memory stick so I'm not worried about losing data but I don't want to go through the hassle of reinstalling 50 programs.