Mobo and CPU recomendations?

I am wanting to set up a linux server for my otherwise Windows office. I just need it for a file server.

I have downloaded CentOS and Knoppix I have tried them on my computer that I want to use and all of them crash. I think there is something wrong with the motherboard.

The old motherboard isn't that great anyways, an old SuperMicro P-III slot motherboard, with a P-III 450. This system used to be a ReByte server and the ReByte started crashing. I thought it was the ReByte at the time, but they reflashed it and I can't get CentOS completely installed and Knoppix running from the CD will crash on me.

I would like to have something newer, but sure don't need bleeding edge. I just want something that will work smoothly with CentOS and serve up files for 5-6 Windows computers to access.

Any Motherboard/CPU combo recomendations? I need ATX size board.

I see some P-4 combos on Ebay that are used boards. I wonder if that is a good choice, or is it probably better to get a new board?

Thanks,

Kirk

Just to throw my 2 cents in, I use an AMD athlon 1ghz, with a via chipset, on a gigabyte motherboard. with a geforce 2 video card, everything linux I try to run works great, and usually everything is detected out of the box.
sometimes have to upgrade the video drivers, but if you are using the box for a file server then this prolly won't be necessary. I've also heard good things about the via motherboards. try an AMD/via combo, you should have a system that won't have to be shutdown for a long time. even just running a liveCD.