Hard drive possibly failing?

I'm not exactly sure where to put this, so I'm just going to toss it here, in hopes someone can help.

Yesterday, my Norton came up three times telling me that incoming data on the port IRC is using was trying to cause a buffer overflow (from different IPs of course), though I'm not sure if this is any part of my problem.. About an hour later after the last one, I got a BSoD and my computer had trouble rebooting. Well, actually, it rebooted 'fine,' but I noticed it would often hang and the activity light would blink on and off for a few seconds.
After Windows loaded and I got to my desktop, it took roughly 30 minutes for Norton to load. After that, anything that Norton would try to scan (internet browser, instant messengers, etc.) would cause the hanging and blinking activity light. I assumed it was corrupted or the target of some malicious program, though the chance of the latter happening was slim to nil, considering I'm not retarded.

I booted to safe mode and ran a virus scan (Norton had no trouble opening the scanner), and it found nothing aside from a hacktool I used for debugging, which I removed anyway. I rebooted normally, and had the same problem.

The next logical step was to run a chkdsk.
I attempted to reboot to the recovery console via the Windows CD, but lo and behold, it tells me I don't have a hard drive. I went back to safe mode and removed Norton from the startup processes, then tried a chkdsk from there. It told me the hard drive was locked out. I restarted normally and tried another chkdsk. Again, it tells me the hard drive is locked out and that it will attempt to do it when I restart.
I restart and the chkdsk runs, but it gives me roughly 500 'unreadable segment' messages and does the activity blinking thing while it's trying to read them, which would make it seem that it's trying to access unreadable sections of the disk when it does it.

So here I am. I've tried uninstalling Norton, just in case, but it refuses to complete the uninstallation (surprise, surprise!), though that's not too big of a problem.
The main problem is that certain actions are causing my computer to hang and do the activity light blinking. So far, I've noticed that trying to copy a file will cause the problem, as well as opening certain programs.

I'm thinking my hard drive or RAM might be failing, but I don't want to replace either unless I'm completely sure and there's no other option.

Any help?

EDIT: Another thing I forgot to mention, whether or not it means anything, is that after a program causes the hanging and activity light blinking, it's icon will turn completely black; it will still have the transparency, but all the color becomes black.