To fix Vista AND replace all the program files I purchased/used a program called "reimage". I have repaired Vista two times using it. It is less than $80/year. They even remove any virus on the computer. The last time my Windows Update, due to a virus damage, would not function and this program fixed it! This program actually replaces the bad files, adds the missing files and re-writes whatever is need to fix Windows Vista. The program will fix this issue and many others. I do not work for these people--I am just a user of it. Be sure, when you buy it, to use a credit card that you do not use often becasue the location of the company is foreign and your credit card company may put a watch on your card. That may limit the card use for a short time....To me it was worth that small agravation. Better, you do not have to know anything about how a computer operates, it does all of it while you just wait---takes about 2>4 hours to run.