sansa express 2GB MP3 player -"unable to open"

Hi,

    I purchased a Sandisk-sansa express 2GB MP3 player some 3 months back.

Now I encounter a problem with it.When I connect the Player to my PC,the device is getting detected.

But unable to open it.Error message stating “Please insert a drive” is shown.

Wat is the problem and how to solve it? Please help!