New PC reboots when I open certain things

I recently built a new computer and it was running fine. I began playing Far Cry and wanted to tweak my Windows XP so that I could maximize the usage of my system. I played around with the services off blackviper.com.

Now, I'm having problems with my computer. If I start AIM or Rthdribl or any games, my computer reboots automatically. I tried disabling the reboot on error for Windows, but it restarts and leads me to some blue screen. I've also tried booting in safe mode, and things seem to work in safe mode. So now I really don't know what's the problem.

Nothing is overclocked.

Specs:
Antec 3700AMB Case w/ 350W PSU
AMD Athlon64 2800+
Chaintech VNF3-250
PQI 512MB RAM
PowerColor Radeon 9700 Pro
Old 40 GB WD Hard Drive

This is where backing up the registry before doing any tweaking pays off.

Best way to start is restore all of the tweaks you did back to the original settings. Either that, do a system restore... or... the fun format.

The blue screen says something about a physical memory dump. I looked on google for any sign of this, and there were some people that said that viruses are able to cause this error. I downloaded AVG and ran a full system check, and it came up with no viruses. Also, when I was doing tweaking, I also changed the page file from 768 MB to 1536 MB. Perhaps this is where the error is coming from? I tried changing it back but it still didn't help.

EDIT: This is what the event viewer says:

The computer has rebooted from a bugcheck. The bugcheck was: 0x1000008e (0xc0000005, 0xbf93179d, 0xaf3fa838, 0x00000000). A dump was saved in: C:\WINDOWS\Minidump\Mini011405-07.dmp.

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

I can simply put the blame to BlackViper because not many of his "tweaks" are good. Go check the OS section to ask the experts who know what they're talking about. In fact many of the Windows services that run by default is needed and optimal enough. You shouldn't be doing any tweaking without any proper research.

-J.

what's the blue screen say...

Beginning physical memory dump
Physical memory dump complete.

well...when you said that you disabled the "reboot on error" thing I thought you were referring to auto restart. Guess not...?

control panel -> system -> advanced -> startup and recovery "settings' -> uncheck "automatically restart"

now you should get a "real" blue screen, which might help narrow down the problem

edit: bah nvm the error is 0x0000008e

well check here it probably doesn't help much..sooo as others have said try reverting back the registry.

I fixed it. I googled the error and it turns out it was my hardware acceleration settings on full. I lowered it, and it worked. However, I wanted the settings on full so I installed SP2 and everything was back to normal again.