This problem still continues...
I was just wondering if anyone would have an idea on what is causing my PC to constantly freeze. What happens is every now and then my PC will freeze and I will be unable to do anything, can't move my mouse or use the keyboard.
When it freezes (the red light that flashes will stop flashing and my PC becomes unresponsive) and I can't do a thing...
Therefore meaning I have to restart, so obviously I do and it will start up normal again, come to a screen where it says start in safe mode etc
but i just go start windows normally. Sometimes the freeze will occur another 2-3 times if not more sometimes after the initial one and i find this quiet bizarre on why and how this is occurring...

I have tried defragging, disk clean up etc. Ages ago my CPU was overclocked but only to 3 GHz so not a massive upgrade...

Then another thing that happens is sometimes upon opening COD4 it will freeze (the red light that flashes remains solid and doesn't flash) and when it comes to the screen where you pick sides for about 1-2 seconds and then it resumes gameplay, i honestly do not know what is wrong with this problem that occurs and was wondering if anyone knew anything about this.

PC Specs are:
CPU: Intel Core2 Duo CPU E8400 @ 3.00GHz (2 CPUs), ~2.7GHz
GRAPHICS CARD: Gigabyte ATI Radeon HD 4850 512MB
RAM: 2x2GB Kingston DDR2
MOTHERBOARD: Gigabyte EP45-UD3L
POWER SUPPLY:
OS: Windows 7 Ultimate 64-bit
HDD: 500GB Seagate SATA (OS + programs and a few games)
1TB Western Digital SATA (Programs, Movies + TV Shows etc)

Be much appreciated if anyone would have a slight clue on what could be causing this.

Thanks

Your specs are almost the same as mine, but i got a much better gfx card, sometimes ill be watching youtube and my pc will randomly freeze and ill get blue screen, havn't figured out the problem, but try cleaning your pc out (dust etc) and clean your RAM sticks carefully.

Also do a virus scan , i preferebly use AVG 2012 (from piratebay shh)

Thats all i can really say, other then maybe thinking about an upgrade

Make sure both rams sticks are still functioning, clean out any dust inside the case that may cause the computer to overheat, if all good then I'd do a virus scan using Malware Bytes and just make sure there isn't a virus on your computer.

Is your hard drive close to full?

Is the red light you are talking about your HDD light? If it is and you have time to I'd say do a re-format. Or you could run a diagnostic on the HDD itself (the one with your OS on it) to make sure it's functioning as normal.

I googled hard drive diagnostic and found this:
www.seagate.com/www/en-us/support/downloads/seatools

See how you go.

Also like the others have said it could be a RAM problem. I'd say try booting and mucking around on just one. If it fails try the other. Failing that though I don't know where you would go from there lol.

Just run a ChkDsk on your HDD, I'll bet it's on its way out. The chkdsk will either repair broken bits or fail, if it fails, get a new HDD.