Would not hurt to do a clean install of Windows then and get a new drive. The Samsung Spinpoint F3 has been the best "bang for your buck" drive for a while now. If you shop around the 500GB is usually about $45 and the 1TB model is usually around $60. They are fast , reliable and silent.
sorry i possted more before reading this. it sounds good in the last week ive installed windows 4 times, both 64bit and 32bit versions. thanks for your help though you are really knowledgeable.