This sound like a failing hard drive to you?

I have a middle-aged Vista machine that I built in late 2008, which was top-of-the-line back then and still works great for most things ... a month or two ago, I noticed it sometimes starting to boot slowly and hang at shutdown, and I often had to manually turn it off by holding down the power button.

Eventually, it froze while in regular operation, saying there was a file system error, and then became impossible to boot. It would get to the green Windows loading bar and then hang on a black screen, or if attempting to boot in safe mode it would hang on the file crcdisk.sys. After a "successful" repair install using the original Windows DVD, the problem reappeared the next day. Subsequent repair installs failed, as well as trying to restore from a system restore point (it said there were none, even though the first thing I did when I got it back was to manually create one).

At that point, I reformatted the drive and reinstalled Windows entirely (took several tries, as it would often hang before the install screen while booting from DVD). This also fixed the problem for a day, and then I got more freezing from a file system error. This time I ran both a WD hard drive diagnostic (it's a WD Raptor 300GB model) and the Seatools hard drive diagnostic, and both found no errors. Also ran Memtest86+ and found no errors.

Then I tried completely wiping the drive by writing all zeroes; that failed. Using Boot & Nuke to wipe the drive clean from a bootable CD also failed after about 30 seconds. From then on, I could not reformat the drive using the Windows DVD nor even get the DVD to boot to the install screen - unless I removed the HDD from the list of boot devices in the BIOS (in which case it did not show up on the list of drives available to install to). I also swapped out the DVD-RW drive for a different one in case that had something to do with it; no difference.

Finally, I put in a hard drive from a different machine (WD Caviar Green 640GB) and was able to install a clean copy of Windows and everything else. I've had no problems since then.

Anyway, the point of this is whether the original drive is even worth bothering with anymore, or if I should just destroy it. In the brief time I had it working again, I did copy a bunch of important data back over from a backup external drive, so I'd prefer to wipe it, but even that seems not to work. It really threw me off that the HDD diagnostic tools found no errors, though.

One other oddity that I noticed: Both times before the fatal file system error, one of the last things I did was install Trend Micro Titanium Security. A little research showed that some users have experienced file system errors from this program if it auto-scans something in Vista that it's not supposed to. But I don't see how that could cause a problem so bad you couldn't even boot from the install DVD, or wipe the hard drive from a bootable CD. Any expert thoughts out there? I have about reached the limits of my own experience.