Getting Kicked to desktop while playing games

[Digitalskull]

I have just upgraded my system.......
Processor: AMD xp2000+
Motherboard: MSI kt3 Ultra with 256 DDR Ram
256 MB DDR ram
Win 98
Graphics Card: Gainward Geforce3 PowerPack Ti/500TV 128MB

I have tried 3 or 4 different games and the sam thing keeps happening...Im able to get the games started but after being in them for a few minutes I get kicked out to the desktop. No messages or anything. I have worked with various game settings to see if it helps and its the same.
A friend mentioned if the system locks that it could be that Im only running a 300 power supply and might need more.....it has only locked once or twice.

Any help, advice or comments would be appreciated. Thanks.

 

[Torghn]

Did you format your HD and reinstall windows after upgrading or just plug the HD into the new system?

 

[Digitalskull]

After we placed everything, including a new hard drive we did a freshinstall of 98 2nd ed. and then loaded the drivers.