If Windows Explorer is being uncharacteristically non-performant, you could try accessing the disk using a bootable Linux, e.g. Ubuntu Live CD...

http://www.howtogeek.com/howto/15761/recover-data-like-a-forensics-expert-using-an-ubuntu-live-cd/

It can be "lighter of touch" in terms of it's I/O demands...

Cheers ;-)