problems with flight sims

Got an athlon 2600+ processor with 512 memory, a nivada ge force 5200 vid card. Running micrcsoft f'sim 2002. Problem is that on modest settings my screen just freezes and I cannot do anything but turn my pc off and start again. At best I take off, fly for 20 mins and then....crash. Can anyone help or does anyone have any suggestions ?. By the way, I think my mother board is ok cos its been just upgraded.

Check and make certain that you have a folder on "My Documents" and if so delete the last flight.
I take you have installed all of the Windows updates, SP1 and the latest DirectX.
Also load the latest sound and video card drivers.
Check and see if you have the latest BIOS drivers for your new mobo.
Put another 512mb in and your textures will render faster.

Good luck and let us know what happens.

just check you have your system updated on windowsupdate.com that should help 2

Strange Fs2002 should fly on the specs you have given us.
Has it allways been like this or is it a new thing?
Have you added anything,aircraft /scenery?

When it does crash, are you flying the same route?

Sorry for all the questions

It may be overheating, check and see if your fans are clean or add another in the rear of the case.