I have been experiencing problems with fs2004 since the first day I bought it. I would be in the middle of a flight and it I hit the ALT key to access the menu the pc restarts, other times when when changing views.
I had directx 9b and it happened regularly so I decided to upgrade to 9c and it still continues to happen.
PC Specs:

AMD Barton 3000+
512 PC2700
Integrated Via/S3 Unichrome IGP with 64mb of shared memory
Windows XP + SP1a
Integrated AC' 97 sound card with 5.1 capabilities
160gb Seagate Barracuda Hard drive.

I was thinking about getting a nice video card but I don't know it'll continue to have the same issue and I don't want to just blow the money.

Thanks in advance.