I just upgraded my GPU (from FX5200 to 7600gs and the minimum PSU requirement is 300W for it).

Well, out goes the old PSU and in comes the new PSU :D

JD, will check the PSU, thanks :) (But how exactly will I know if something's wrong with it?)

Samerzz, yup I did all that've mentioned. Checked for the thermal grease on the CPU and did find it (though not much; maybe I need to apply some more?)

The memory's fine. Its 1gb and it shows 1gb and in CPU-Z, it says everything's alright. Not sure how I can prove that it's working ok, though.  

Yes, my comp locks up for every game, be it a taxing game like FEAR or virtually no "power required" games like Quake 3 or Mortal Kombat 4.

Yup, I do have the most current drivers that are released for my GPU, mobo and sound card.

Like I said, if it involves video output, more often than not, my pc locks up, even for MovieMaker (though its random for MovieMaker and doesn't happen always). I can run Winamp, spyware detector, anti-virus, photoshop and paint simultaneously for hours (for example) and nothing happens. Just that my PC locks up while playing games almost at the same point of time.

I'll tell you the problem first....

If I play a game non-stop for more than 20 minutes, my PC freezes and the only way out of it is to press the "restart" button. Once its on again, playing the game for approximately 15 minutes again freezes my pc. If I use photoshop or programs like that for hours on end, nothing happens. However, using MovieMaker sometimes, and I mean sometimes causes my comp to lock up and stop responding.  

My rig's a P4 2.6ghz, 1gb RAM, Nvidia Geforce 7600gs 256mb 8x AGP, Creative Live! 24-bit with 5.1 400W Inspire speakers. I've checked and re-checked them all and seems like they're working ok.

I did format the disk and reinstalled XP Pro Sp2 and all the programs I had. What I wanna know is, even though my GPU has never gone beyond 65 degrees C and my CPU seems to overheat more than normal but not too much (I think), is overheating an issue here or are some codecs used to play compressed videos, messing with the system?  

My rig : P4 2.6ghz, 1gb RAM and 7600gs 256mb 8x AGP.

I've made a few gameplay videos in the past with a 6600 and FX5200 and though the frame rates were under 35 most of the time, I knew the cards weren't great to capture at 35+. When I play Quake 3, I get over 90fps but I start recording with FRAPS, it drops to 21. I mean a 70fps drop is unheard of. I'm sure none of the memory consuming background tasks like anti-virus and spyware protection programs are running. What could be the problem?

My PC's specs : P4 2.6ghz, 1gb RAM (2x512mb DDR) and Nvidia Geforce 6600 256mb 8x AGP using Win XP SP2.

For the past 3 days, my pc's been freezing randomly. If I don't play games, then its just fine when I work on Photoshop, etc. But when I start gaming, it hangs up randomly. When I play games like QUake 3 and Enemy Territory online, it locks up when the server changes the map. When in offline mode, the comp locks up when I quickload 3-4 times while playing games like FEAR, Quake 4, SPlinter Cell, etc. If I don't quickload, then there's no problem. The new level loads pretty quickly and everything's fine.

I never had any problems like this before. I checked to see if the memory stick is lose (just in case) but its tightly placed in its socket. No overheating. I think the RAM's messed up (been over a year and a half). Any ideas?