I've been having strange graphics glitches in the past and received some awesome help in picking out a new power supply and was hoping to dip into the well again.

Now, I'm not 100% positive that the HD is the problem, but it sure as hell seems like it must be. My computer recently started to hang during common everyday use and it seems to be getting worse. Originally, I thought it had something to do with the new power supply I had put in but I think at this point, I can prolly rule that out.

I tried running a game to see if there were any similar oddities to the ones I've been getting recently during testing of my game and something really screwy happened. For starters, L4D took upwards 10x longer to load than it used to, and then once in game, the first gunshot sound began to loop indefinitely and the screen froze. I was still able to alt+tab out, but then everything else was all super janky. Like, clicking on the Start Circle on windows 7 bottom left took half a minute to register and load up the start menu. I did a reboot, and that took exceptionally long. Then when I got to the log in screen where I choose which profile I want to load, clicking on a profile lead to another minute long wait to get to the screen where you enter in your user password. I mean, I have no clue what the hell is going on here and the best I can come up with is something crazy must be going on with my hard drive. After finally booting up Windows, everything is slow as hell and basic startup things take a looooong time to load up. It seems like once things are up and into RAM, they run fine but I feel like anytime I have to access new memory from the HD, the computer sorta freezes up for a while. Though, it's not a complete freeze since I still have mouse control.

Does anyone have any suggestions on how I can figure out if this is really an issue with my HD? I'm worried so I've already started backing up important files to an external HD I have.

I'm open to any and all ideas. If anyone thinks this is something other than the HD acting up, I'm all ears. I may just go ahead and pick up a new HD tomorrow but the idea of reeinstalling everything just hurts my head. Also, my desktop was originally an HP so I don't even think it came with OS cds. . . so I'm not entirely sure what I should do to reinstall my Windows. . . Anyhow, give a duder a hand =)

Yeah get everything you value onto additional storage devices.

You could run hd tune which is a benchmark program for hard drives. Run the read test, and then link/post a screenshot here for us to evaluate, but dont do that untill you have everything you want backed up. If the hard-drive is going, the benchmark might just push it over the edge.

And if you arn't already monitoring your temperatures, get HWMonitor for that job.

As for the reinstall, you should be able to view your cd key if you go into control panel -> system , alternatively right-click on "computer" in the start menu and then hit properties.

after that just borrow a windows 7 dvd from someone and use your prior cd key.

Usually when the system didn't come with the windows disk it has a recovery partition that you can access at boot by pressing F11 or something like that (there will be a message at boot telling you this), then it recovers your system to factory default.

Check the system logs they may be tell you what the problem is, go to "start menu > control panel > administrative tools > event viewer" then expand "windows logs" and choose "System" check for any errors, if there was a read or I/O error it will be there.
 
If the problem is indeed the HDD there is a very neat program called HDD regeneratorit's a bit pricey but it sure as hell works like a charm, unless the HDD has a actual physical problem with the motors or whatnot.
 
But the problem could be overheating for example, so install CPUID hardware monitorto check the temps at idle and at full load.
 
Also it totally could have something to do with your power supply, I recommend getting a 600W PSU from a good brand like corsair for example, it will cost you I think less than 60 bones.

How much wattage does your power supply have?

Also, it sounds more like a cooling problem.

Have you tried CTRL ALT DELETE and running the peformance manager under the performance tab and sorting for CPU? It could tell you if you have any programs/processes that are eating up you cycles. You can also suspend or end it from there so you can tell immeadiatly if that was your issue.