amiforsaken

Hey, I have a problem. I bought recently a Maxtor external 500gb usb hard drive and then started having troubles with my USB ports not working. As a desperate need to access my data on the external harddrive, i cracked it open and took the SATA harddrive inside of the enclosure and plugged it directly into the SATA onboard port on my motherboard. I started my computer and windows xp now takes an extra 5 mins for it to boot. It shows in Device manager, however it doesnt in my computer and doesn't in disk management either. I checked on many forums and all said that formatting it should fix the problem, but if it isnt showing in disk management, i cannot format it. I am at a loss on what is wrong and how to resolve it. If someone could give me insight, it would be much appreciated. thanks.