Passport Essential works with XP and now not with Win8

Portable Drives My Passport
1

I have two Passport Essentials, a My Book 1TB and a My Book Live.  Until last week they all worked with my Win8 pc.  Now one of the Essentials can not be seen.  However, when I use my wife’s XP machine everything is there. 

Anyone have any ideas.  The others (Essential, My Book, & My Book Liver) still work just fine with Win8.

SSANUT

2

http://wdc.custhelp.com/app/answers/detail/search/1/a_id/5419

Go to device manager and chesck if there is a yellow triangle listed on universal serial bus controller. If there is download ses driver. Also if you are using a laptop make sure that the laptops power adapter is directly connected to a wall outlet.