Computer Freezes when running games

I am setting up a second computer for my children to use and primarily play games on.I did a clean fresh install of Windows 98SE and all works fine except when they try to play a game.The system runs fine for hours until they play any games.When a game is started it loads and runs fine for about a minute or 2 then the whole system locks up and the only way out is to cold boot.Ctrl-alt-del does nothing.I have tried using different versions of graphics drivers but always the same result.The game requirements are all under 400mhz p2 and the graphics card should be way more than sufficient.The graphics card is good because i used to have it installed in a different comp previous to this one and never had any problems with it.I have tried lowering the hardware acceleration but the same problem exists.Any help would be greatly appreciated , Thanks .
Make -ASUS P2B-B motherboard with the latest Bios update installed.
CPU - Pentium II 400 mz
Ram- 2 X 128 mb Sdram
Hard Drive - Maxtor 20 g 7200 rpm (free space 18 + gb)
Windows Version - Clean full Install of Win 98SE
Internet Connection - none
Not connected to internet and no anti-virus installed
Graphics Card- Geforce 2 MX 400 64 mb Nvidia with the latest Detonator drivers installed.
Direct X 8.0

i get that EXACT same problem…if anyone knows how to fix it, id be greatful as well.