When I connect to My Book it doesnt not read the

If you are running Vista, You might be one of many people who are reporting an update that is causing some buggy behavior. Try this:

Connect the drive but do not Format the drive, right click 'my computer' then 'manage' go to 'storage/disk management' view the drives; your usb drive will not be allocated a drive letter. You can set one manually or leave it for about 2~5 minutes for one to be allocated auto. Each time you connect the drive you may have to do this.

OK, For All so-called Experts, Read Up on The Drive Model Details First.
The MyBook World Edition is a NAS accessed via network only.
The USB connection is for an additional drive only.
Therefore all these 'Answers' refering to Windows USB issues are superfluous.

If the Blue-Ring Flashes it is usually an indication of the Internal HDD overheating - or at least the sensor reacting - perhaps prematurely.
Especially if it works ok for a while then flashes.

1 - Try vacuuming the drive around all the vents to remove as much dust etc as possible - even if in psuedo dust free enviroment - we all shed skin, otherwise there would be very little dust around.
(Just putting on my isolation suit to go to the spare room darling...)

2 - Relocate the unit if horizontal, then vertical and vs. versa. AND to a different location even move to a clear(er) area and blast with a fan - see if it lasts longer.

3 - If in warranty back up your data (with item 2 above)(how ever tedious) AND get it replaced. Yes, buy a backup for the backup if need be !!

4 - If out of warranty OR you want to try (all disclaimers apply) OR you don't care - but are interested follow the wiki hack mybook site and hack into it via SSH and treat it as a new non-wd drive and disable 'S15wdc-heat-monitor' in the '/etc/init.d' - just to seeif makes the blindest bit of difference - if it does then it's a good workaround to keep the drive alive to backup all data whilst considering replacing the drive (identical make & model preferred) or at least acknowledging the sensor within may be at fault. If your that concerned you'd get detail on how to open the unit up and manually monitor the hdd temp to rule out the internal drive sensor fault.

Food for thought.
JonT