Replying to Somethings wrong with my computer....

please read guys, i need your help.

so my Acer is acting weird... its running XP with sp2
so im good with computers and ive tweaked it here and there. yesterday, my norton antivirus would pop up when i tried to open firefox, and it saidlike, antivirus cant use the repair function.... so i clicke dok and i had to reinstall firefox. then all yesterday, every 15 minutes a Scanner Module pop up would come up from norton.... so i was a bit confused. i was gonna uninstall it, but i had no time. so i woke up this morning, and i clciked on my zune software on my taskbar, and it said, unable to locate path, so i browsed, and found it, but it still didnt work. then i noticed the majority of my programs are those little windows, instead of their icon. i went to add or remove programs and i clicked remove norton, and it said it was already uninstalled. it said this for almsot everything.

the only programs that are working for me now are firefox, msn and winamp. obvisouly theres more but this is fucked. can someone pleaseeeeeeeeeeeeeeeee help!!?