Does your external have 2.5 or 3.5" drive ?
Thank you for your reply. My laptop has an internal 2.5 drive and I'm thinking in buying a 2.5 external USB drive. Was this your question?
Does your desktop have the necessary mounting hardware for a 2.5" drive ?
yes, it does (I'll be using the FDD mounting for it).
The definitive HD tool is SpinRite but it's not freehttp://www.grc.com/sr/spinrite.htm