Friday I bought and downloaded Doomsday and Armageddon from GG. I installed DD, patched it to 1.3 and tried playing it. When I click single player, everything looks fine but as soon as I click a flag my monitor shuts down. I tried this multiple times, with different flags. Sometimes I can still hear music playing, sometimes I can't. I also once got a warning on my monitor saying something about "out of range" and then something with frequencies. Before I could figure out what it meant, it was gone.
Also, the first crash reset my BIOS settings to default (which is kind of strange I guess). I set my BIOS to the right values and none of the later crashes reset them again.
The tutorial plays fine (although I did not run through all the missions, but at least I could normally load one).
I uninstalled DD. Updated my Video drivers. Installed DD, ARMA, and ARMA 1.1. It worked fine once, but then the problem returned.
Here are my specs:
Windows XP Pro SP2
AMD Athlon 64, 1800 Mhz, 3000+.
1 Gb Ram
ATI RADEON 9600, with Catalyst 7.11 drivers (newest available)
Realtek AC'97 Audio
Please let me know if you need some more information. I hope that you can help me because I am really looking forward to playing the game!