hardware advice

[bearded]

i'm trying to play the marvel vs trading card game for pc, as well as the game overlord.  my regular system can't handle it, but i have a very nice agp graphics card in another system.
looking for help on various subjects;
i tried using 3d analyzer to get the games working, but not enough raw power to fake the settings for those 2 games, although i can get marvel ultimate alliance up and running, just barely.
the big issue is my alternate system.  it's got the power but something is shutting it down.  it will boot almost to the windows load screen, then reset, turn off and immediately start booting again.
does this sound like a power supply issue?  i can't even get into bios to check things.