WD 640gb my book not seen in my computer on my desk top, it seen

Best to go threw the manufacture with original parts.

If the drive does not appear in Remove Device but does appear under computer you can right click on it then select EJECT.

change your usb cable, mostly the issue is with the usb cable

Try plugging the usb cable directly to a usb port on your computer and not through a usb hub. Also make sure the ac adapter for the Western Digital is getting power and the light on the drive is on. Also a recent update to your virus program could be blocking it( it happened to mine).
Thanks for using FixYa

Your WD HDD have been attacted by viruses for your computer or outside computer where you used it last. Make sure that you have an up to date antivirus software, scan your computer or the external hard drive, explore your computer, go to tools - folder options under view files & folders select show hidden files and folders apply and ok it.

External hard drives don't need any program installed on your computer to run. Your operating system Windows, Linux should handle it as soon as you plug the usb in your computer. The programs included in your WD external hard drive are tools to backup your data.

If you try to hook up your hard drive to a Windows prior to XP, maybe your computer will not handle it.

It is always safer to safely remove your drive using the green arrow icon in the lower right corner of your screen. This way, the drive is shut down properly and you minimize chances of fails when you plug it again on another computer.

Hope this helps!

Have you tried searching on ebay?

files must be "imported" into your new mail program.
the new computer may have a newer or different version.

This is a common problem with the WD external hard drives suddenly not working. If the computer does not recognize the device anymore, then there is a problem with the WD's hard disk enclosure (not the hard disk inside). If this is under warranty, you can bring it back to the store and ask for a replacement of the enclosure ONLY; then put there your existing 1000 GB hard disk that's inside the faulty WD external.

If its no longer under warranty, you need to take out the hard disk inside the WD enclosure and mount it to a desktop computer or place in another vacant hard disk external enclosure.

does your wd external hard disk use external power or bus power.... if it uses external power this effect could be due to feeding of power from the external power to the usb port...