Whenever I click on my desktop icons, they all dissapear along with the windows taskbar and the program dosent run,however all the programs I already have running stay open. Usually they reappear after a few seconds but sometimes they dont come back. If I run the explorer prgram through the task manager they come back but the problem persists. This dosent happen for all the icons just most of them. Firefox WORKS along with a few anti-virus/spyware programs i recently downloaded. More recently my task manager has become messed up. The blue bar and the tabs at the top have dissapeared so I can only veiw applications I have running. Also Ive randomly lost all my FAVORITES, search engines, bookmarks ect. on firefox.
Any help would be greatly appreciated.

Computer specs(sorry I dont know to many specifics, Im not sure how to look at them since I cant get into control pannel):
Dell Dimension E510
Windows XP Media Center
 Intell Pentium 4
512 MB RAM
160 GB harddrive
I have Trend Micro Pccillin but its been out of date for a while
Ive downloaded the free anti virus/anti spyware programs reccomended on this site and am in the process of running themWithout an up to date antivirus and spyware protection being used regularly you are an accident waiting to happen. WHen you are clean of EVERYTHING (and you list  the programs you used) then all bets are off and we can't proceed.  Ok Ive gotten Spybot, Windows Defender, and AVG free edition. AVG is still running and  has already found  about 100 infected objects. There are multiple "Klone" viruses and "Generic" trojin horses. Im not sure if that helps, is there anyway to POST the results of the scan when its finished?ok did a search on the klone virus, and there are others that report getting winantivirus popups which I get all the time. I thought I stoped these with spybot and Windows defender but I keep getting them. Dont know if this relates to my other problems though.Scan in safe mode.ok results in a whileSorry for the long delay. I scaned again with AVG and the 190 or so infected objects is down to four, all Klone virus. I got rid of these so is my computer clean now?
 Also while in safe mode my desktop kept dissapearing, this time after just a few seconds. I kept getting a message that asked me if I would LIKE to work in safe mode. If I clicked yes my desktop would come back for a few seconds and the message would appear again. Is this normal?With such a compromised machine I would format and reinstall to remove ALL infections, but that;s just me. Some people like to patch together a (mostly) workable solution.Being a thrillseeker I decided to Google winantivirus to see if anythinh had changed. (Nothing has)
I clicked on a Google link to the winantivirus homepage and would you believe Google intercepted the winantivirus homepage, put up a warning and gave me an opportunity to chicken out.
How cool is that? Check it out.
http://www.google.com/interstitial?url=http://www.winantivirus.com/
I'm off to winantivirus now to test my bulletproof IE *gulp* if I don't come back here's a link for you.
http://www.bleepingcomputer.com/forums/topic18610.html