Please help. problem in XP

My antivirus detected a trojan virus yesterday and removed it. However, since that time, Windows XP Search will not open. I am unable to search for any files or folders since it won't open. It's just blank. Also, Help & support won't work. I can't view several of my favorite web pages. they won't load at all. I can view many others though. I can not download any patches or fixes from microsoft, and I also can not submit info on some sites (drop down bars are blank)....also I can't save some of my passwords. System restore won't work either. PLEASE tell me what to do to fix this. If anyone knows, or has had this happen to them....I really need some help. Thank You!!!