I've just done my first home build, the computer turns on and gives various messages about the hardware. I was under the impression that to install XP you just put the disk in and followed the instructions, but when I put the XP disk in (it's from an old Dell PC) nothing at all seems to happen. Also, the USB ports don't seem to be working since my mouse and keyboard aren't coming on when the PC comes on. Any help appreciated, thanks.