HD question for you pros

Hey, I Got a computer in late summer, it had vista on it, I fdisk'd it in an attempt to install xp. When I started installing xp, it would load the setup files tell me it needs to restart, after it did the start the process all over again. I went into fdisk to see what was going on and I got an error saying the HD isn't bootable because there isn't an active partition. Ok simple I went to "set active partition" and I got an error saying "the current drive is fixed: 1" and fdisk freezes and I have to restart. I've been fdisking computers since windows 98 and have never come across this problem, I thought maybe burning and using a bootable copy of partition magic would do the trick, but all I get is a "partition table error" I don't remember which error # it was, if anybody knows wtf this means I can hook the HD back up and see what it says. I am currently using an old HD that is a scsi. The one that isn't working is a seagate barracuda, if that makes any difference. I'm looking to set this segate to active partition and make it so that Windows will run on it.
-thx