problems with FS2002

I have FS2002 Professional. I will be playing it when after awhile (it can be two minutes or an hour or more or less) the computer will suddenly restart. I did not encounter this problem until recently and have not had problems like this when I use other software except with some college software I had to use. Any ideas how to fix this? thnaks

My first guess (without knowing your system specs) would be that the case and heatsink fans are in need of a cleaning.
The sim has a habit of running hot, if dust prevents it from cooling the sim crashes.
Clean out the case and if you can add a case fan in the rear to expel more of the warm air.

Let us know how you do.