But none the less here you need to remove the HDD from the system fit it to either a Suitable USB Enclosure or a Universal USB Lead and then copy the Data as Plain Data unencrypted/compressed to some different media.
If you where employing security like a Password you'll need to Take Ownership of the files/Folders. But depending on what your OS on this drive is the directions are different.
Here are the XP Directions but if you don't have XP you'll need to look up the directions for your OS
http://support.microsoft.com/default.aspx?scid=kb;en-us;308421
As for USB Enclosures/Universal Leads look at these places
http://www.cooldrives.com/sata-enclosure.html
or if you need to use this drive for long periods of time you should consider a Actively Cooled Enclosure like the MX1 from Antec
http://www.antec.com/Believe_it/product.php?id=NDc=
http://www.newertech.com/products/usb2_adaptv2.php
Col