I took an old hard drive out of my old computer tto install into this new set up. It is a Maxtor Diamondmax 10 drive model # 6V200EO SATA II drive I plugged directly into the mother board. When I connected it I assumed that it would automatically detect as the slave ( it also has windows xp on it), It booted through the 1st drive hit an error and then rebooted again onto the ssecond drive ( the one I'm trying to install as the slave). I shut down and unplagged the HD. Started back up and then plagged the "slave" in. It saw the " slave drive". Do I need to remove windows from the "slave drive", is it a bios setting I didn't do or something else I'm missing.

Your BIOS should have a second option to select which hard drive to boot to first. You need to be sure it is set for your original drive. You shouldn't need to remove Windows from the second drive. Check your manual to see what SATA ports do what. Some boards have some ports that don't support a boot drive. That would be the place to connect the second drive. Also, you may have some settings in the BIOS configured for a RAID setup. When you only had one drive it didn't matter but with two it may.