I just resurrected my old HP from the dead, and even though it looks like **** and was left out in the rain (Just the mobo and case) it works.
I'm going to turn it into a home media server, with a 160 gig HDD. I have no idea what OS would be best to do this however. I'm not averse to Linux, although I would have to learn a lot since I don't use it at all.

Also a problem- for some reason it forces me to have 1 stick of PC4200 DDR2 ram in. It will not allow me to have 4 sticks of 6400, even though that's what I did before. Whether I have 1, 2, 3, or 4 sticks of 6400 it just blares at me untill I turn it off and put the 4200 back in. The 4200 is what came with it, but in my years with it i upgraded from 4200, to 6400. Which worked fine for years untill now.

Thanks.

If it's an old piece of crap, Linux will serve it best I guess.

Otherwise, Windows Home Server is also a good choice.

Not really crap, Duel Core AMD 4800+ on an Nforce 430 with onboard Geforce 6150. 7 gigs of ram (3 Sticks of 2 gigs and one stick of one gig due to the aformention problems) 160 gig HDD.

edit: I guess it helps to read the OP

Windows 2000 Datacenter Server Edition.

I agree with everything you just said.

I finally set up my first MythTV box at school, and I will probably use XBMC if I ever made one for myself.

Ubuntu ftw.

My PC had all kinds of problems with my three 512 sticks until I placed them in a specific order. Probably problems with different timings which you shouldn't have. Maybe one of the sticks went bad? Try using different combinations of the 6400 sticks until it boots.

I should mention I know nothing about home servers so I wouldn't know which OS is best.

But I think this is relevant: http://windowsteamblog.com/blogs/windowshomeserver/archive/2009/11/22/try-your-hand-at-a-home-server-haiku-ie-a-contest.aspx

Well, I'm using home server and it works great.
I'm pretty proud of myself for literaly taking parts out of the garbage and throwing it together to make something useful. I should take some pics of it.

cool we've never seen one of those before

But it's special because it's mine.
:Colbert:

WHS is pretty damn good for what it does (it's basically Server 03 with some extra stuff built into it, and a few things taken out). I've got one running in my house that takes care of backups for all of my computers, as well as works as a pretty nice file/media server.

i've been tempted to switch my server to windows, but I have 10 ext3 drives

There are a couple of ext2/3 file system drivers for Windows. But I don't really know how good they are (when I've written data to the disk fsck always fires up next time I boot from it...).

Hahah, you make me laugh good sir!