WD Passport Essential SE Smartware Not detected

I have a 1 TB essential SE with smartware. Suddenly it is not being detected by my laptop. It was working fine till today. Any idea what might be the problem?

Have you tried a different USB port or USB cable ? Can you hear any odd noises from the passport ?, does it feel like its operating (be carefull not to bump it while it is on, a slight bump/knock can kill it while it is on).

What does the drive mangment tool show, is the drive there but without partitions or just not visable at all.