Lost Internet explorer

Hello, A few weeks ago I had an automatic upgrade from Windows Vista. Ever since I've had nothing but problems. I lost my Internet explorer as well as other programs and can't seam to find out why or what to do abgout it. My virus scan find no virus but on the other hand I'm not sure it is working. I have had a friend who knows computers but after several hours we are coming up with nothing. I do not like Vista and would prefer to have my XP back as it was more operator friendly.

smurf