Since I got my PC up and running a few months ago, I have experienced Blue Screens of Death (BSoDs) quite frequently on Windows 7 - every 4-7 days. Needless to say, that was annoying, since it interrupted whatever I was doing at that time (luckily I have not once lost any data - UnrealEd 1.0 taught me to save my work often :) ). Before BSoDs I can always see screen corruption - as if all of the screen suddenly turned into a chaotic mix of lines that have the colours of whatever was last displayed on screen. After that, all BSoDs had different, random errors - very inconsistent overall.


At first, I thought that the cause was software. I have quite a lot of drivers that aren't very reliable installed here (after all, Windows 7 is still brand new), so my suspected programs were Creative Mode Changer, Creative Audio Console (the Creative sound card driver), ATI Tray Tools (those use its own driver to override Catalyst, and it's unsigned, and Micro$oft obviously are very greedy and completely disabled installation of such drivers unless the creators pay them - just one of the things on this OS that really annoy me) and, due to graphics corruption, ATI Catalyst. I had a plan of turning off those programs one by one to see if that changes anything.

However, while I was doing some research on the possible BSoD solutions, I found out that a rather common cause can be bad RAM. RoninMastaFX also noted that, so I decided to try out Memtest86+. One thing that I like about it (and the GRUB boot loader - it's so awesome I can't imagine a system without it) is that you can put it on a flash drive and boot it, even without the need of any reformatting! The procedure is described here, although I didn't follow it directly - it's really not that much of a hassle to simply enter those four commands into the GRUB command line each time you want to boot the test.

Even the first 2 test passes (no, passes don't mean that the test is successful, it's their word for iteration, basically) showed that the RAM had errors. I've decided to investigate this problem more thoroughly and tried all kinds of different settings in both BIOS and physical RAM module placement. You can see what I tried here, but in a nutshell, I tested it at least 15 times with 5 passes on average. And, in fact, it failed almost all of the time; but I thought that both modules, when inserted one by one, pass the test - that was my mistake that took quite a while to find, since I only tested them by running 2 passes, and one module just got lucky. I also tested the system with Prime95, a program I can highly recommend - if you can run its stress test for 8 hours without having even one worker dead, then your system is perfectly stable. If even one worker dies, you should consider looking for the cause of the error.

In the end I managed to find that only one module was bad, and I'm returning it to the warranty service right now. Meanwhile the computer is running on half the memory and quarter the speed - right now, for example, I have 6 MB of free memory left, and even when it's on a clean boot, Windows 7 Ultimate consumes 1500MB of memory! Needless to say, that is hardly an optimal environment for mod development - after all, it takes a lot more time to test the code that way, so expect delays in my projects. But at least it's perfectly stable now and it passes both Prime95 and Memtest86+ tests with flying colours!

I'll post again once my RAM module is replaced or fixed to let you know.