Hi everyone I want to thank you in advance for reading this and offering any advice.
I have a kinda old self-built computer that has been very reliable for the last two years. I've updated some hardware on it but nothing recently. I recently installed Fallout 3 and NeverWinter Nights 2 and both of the games have frozen fairly randomly, let me give you the specs and I'll dive into that further.
The computer specs are:
Windows xp pro sp3 (fully updated)
AMD athlon 64 1.8ghz processor
ASUS a8n-sli mobo
1.5ghz DDR 333 ram
NVidia GeForce 7600GT (newest nvidia driver)
Creative SB Live! (updated drivers)
I recently installed Fallout 3 and after a few hours of playing it started to freeze. The screen wasn't loading textures properly and movement was very slow and choppy, the audio went to full volume static, and sat there. I was able to alt tab and go to windows desktop but it was still producing the sound and fallout 3 was open so I ctrl alt delete and exited fallout 3. Then I figured I'd just turn off my computer for the night and try to find what errors are common in fallout 3.
In the morning I go to boot up and it wants to run a chkdsk so I let it go through that and it replaced some registry files. Then as windows is loading there was an error that a .dll file was not found and it automatically went to reboot. I ended up installing windows on my secondary HD and I attempted to recover data off my main HD but it said the drive has not been formatted would like to format it now.
A few days later I reinstall fallout 3 and the same problem happens again during gameplay. This time the windows file in system32/config/sys was corrupted. I reinstall windows again and I assumed it was fallout 3 having some error so I didn't reinstall it again. Instead I picked up Neverwinter nights 2 and just last night it had the exact same error except I didn't shut down the computer until this morning and I didn't have to reinstall windows although a couple registry files were corrupted.
My ideas on the issue: It could be a bad video driver, the cpu could be overheating (although I checked the heatsink and it's still seated properly), the video card could be overheating (although I have 4 fans throughout the case), the sound card is old and could be going bad. I just have never seen random windows system files be corrupted and this type of freeze where the screen doesn't go black or to the bsod.
Seems your copy of Windows is corrupted. From what you write, you're experiencing missing system files. I doubt that it's your Windows installer that's the problem, since it's on a non-writable disc, right?
Anyways, why don't you try a totally clean install? Deactivate one of your hard disks, and install Windows on that, making sure to completely format the hard disk in the Windows installer. I have a feeling there could be a virus or malware screwing up your system.