Basically stated Tom, buy a new hard drive and transfer all of the good stuff to the new drive, not too tough, I would recommend picking up one of the small pocket drives, I use a 250 gb drive and just have all of my data replicate every day, no way to lose anything because I have it twice...
Your hard disk has a "fuzzy" spot on it, and will fail real soon...Not uncommon at all, sometimes if you run a scan disc on it you can relocate items on the drive to avoid the "pitfalls", called partitioning, I have had zero success with this, a new hard drive can be had for about a hundred bucks....If there are Guru's in your area, have them swap it out, but don't forget to relocate all of the info you want to save...Oh yeah and don't run Symantec anti virus if you're looking for a fast 'puter, it runs way too much BS and eats up horsepower...McAfee is the bomb for high performance computing and is safe IMO.
Good luck!
GT