Crashing

[Jqwerty]

I have looked around on the technical forums already for possible ways to fix this, but it seems no one has had my situation.

I had no problem creating my character and logging on. Everything works smoothly for me there. The problems start happening when I press the dreaded "Play" button.

I see the loading "Regnum Online" screen and it loads various things on the bottom for about ten or seconds. Then it does one of a few different things.
~Then my computer restarts. (still seeing the loading Regnum page)
~My game crashes with the Error message saying my program crashed
~I see the game interface for a few seconds & my PC restarts

Then I try to log on again and it says I'm already logged in.
(I can re-log in about five minutes though)

I've tried to install the DirectX Runtimes for June 2007.
I've tested it on OpenGL & Direct3D with different screen size resolutions.

My system's diagnostics look something like this.

OS: Windows XP Home Edition
BIOS: Phoenix - AwardBIOS v6.00PG
Processor: Intel Celeron CPU 2.80Ghz
Video Card: Nvidia GeForce FX 5200
Memory: 512MB RAM
Direct X Version: 9.0c
Sound Card: Realtek AC97 Audio

If you have any suggestions please feel free to post them. I was looking forward to seeing if this game was any fun, but I can't even get into the game.

~Josh