Essential USB2 not accessible after I attached new Ipod shuffle

I’m not very good on anything but basics but after I couldn’t read my trusty external drive any more (which has all my documents, photos and music, help!), I assumed that the driver was corrupt.  I tried to download a new driver from this website for my 4 year old drive, but the only one I could find was for Windows 98 and not for 2000.  I am currently running the diagnostic program I was able to find.  It currently says under SMART status that status is unknown.  I would be most grateful for ideas  what I can do to see whether the drive is corrupt or the way in which it connects to my computer and how to recover my stuff.  I had hoped that by shutting down the computer and the drive, it would kick back in, but it hasn’t.

Try to run the Diagnostic software that WD has the Website:!&p_li=&p_topview=1