BleepingComputer.com: Hard Drive troubles

My problem is i have a new windows vista computer. I had a year old dell that was running windows xp with one 160 gig sata maxtor hd. The motherboard went out and i decided to get a new laptop. I need to get the data off of the old hard drive and put it onto my laptop. I have an external sata hard drive case so i hooked the old hard drive up to it and it to the laptop by way of usb. the bios shows it is there and the disk management shows the external hard drive without a letter and the only option i have is to look at the properties of the drive or delete the partition on it. But "my computer" does not show the hard drive. i was wondering if the problem lied in the fact that it was a c drive and now wont show up because there is already a c drive on the laptop. I would really appreciate the help in getting my computer to recognize the old hard drive so i can get my info off.

Go to your start menu and in the run box (or hold down your windows key and press the R key) type dismgmt.msc and press enter you will see a list of drives. See if the USB drive is listed and what are the entries next to it.