[CentOS] Installation failure

I'm trying to reinstall CentOS on a machine I've reconditioned for it,
but for reasons I can't fathom, when the installation disk comes up
and prompts for the install type, and I type either <enter> (graphics
isntall) or "linux text"<enter>, after it loads the initrd image, the
machine shuts off.

It's an older machine I built myself (and ran CentOS on for a number
of years), AMD Athlon 64 x2, 2GB of memory, 2 SATA hard drives, ECS
GE6100PM-M2 motherboard.

I should probably even know the answer to this one, but I'm stumped.

Any suggestions?

Thanks.