Yesterday night, i start up my computer as usual.. it was working fine until i sign in msn.. thats when the problem came in.. The computer start to restart itself and i have no idea why.. So i waited for the computer to boot up again... but after a few minutes, this problem continues... and it restart again.. then before i get into windows... i came to this screen saying that my system file is missing so i repair it by inserting the windows xp cd rom and press 'r' and the computer is able to boot up to desktop but i noticed some of the icons in my taskbar tray had gone missing.. for instance my wireless linksys icon and the sound tray icon is gone.. and i couldn't run my avast.. I tried to open a song on my computer and the program will stop responding.. same goes to other programs.. it would just hang here... i can't proceed further.
Sorry i'm not really sure what the problem is.. and i don't think i went to any malicious websites earlier on... Please advise me on what i should do? Or should i just reformat my computer? Thanks for any help... very much appreciated.