I use a My Book Essential 250 GB external hdd to store system images made using Acronis True Image. I only attach the drive once the computers are up and running and then disconnect it once I've made a backup/image. When I plug the drive into a USB port it takes a long time (2 minutes or so) before the drive is recognized and usable. Once it's up and running all is well. I've attached the drive to 2 other computers running Windows 7 and get the same behavior. When I attached it to a computer running Windows XP the drive is recognized right away.

I have a dual boot set up for my laptop Win7 and WinXP. I get the same performance as described above - with WinXP it is fast, with Win7 it is slow. Clearly not a hardware issue since nothing changes but the operating system.

I have a couple of other WD external hard drives (WD Passport 250 GB and WD MyBook Home Edition 1 TB) and they are recognized and usable right away. There is something about the Essential Edition and Win7 that causes the delay. Just not sure what.

The drive in question is a couple of years old and is formatted to NTFS. I've tried reformating via Windows 7 but no change.

Not a big deal but if anyone knows why this happens I would like to know.

Thanks.