Larry, I believe that you are right. Bad clusters would make since being the smallest unit for storage in a file.It shows Windows has corrected the file system, I guess that just like saying bad clusters. Anyways I backup critical data and I believe this Hard drive is toast. I will play around with WD/HDD on my bench model. I am repairing this to prove a point, that the thing does not need all new guts as one PC repair shop wanted to do. My friend built it and I think even though it is a few years old it still has some life left.Thanks for fast response time and you confirmed what I was thinking, that the hard drive is going bad.I believe this to be the best site that I have used to get quality information