WD external hard drives only detected when I restart the PC

Hello Users,

I have 4 WD external hard drive(ranging from 500GB-3TB) and all of a sudden from 26th January,2013; I started receiving this very wierd issue.

When I plug in any of my 4 hard drives in my desktop computer(Windows XP 32 bit SP3) and start the computer, everything works fine. But if I remove that hard drive and reconnect the hard drive back, it does not show up on my computer but again if I restart keeping the hard drive in the same port, it works again. Due to the nature of my work, I have to remove and plug back external hard drives plenty of times during the day and restarting the computer is not a very elegant solution. I have ensured that this is not related to my hard drive itself because I can plug in the same hard drive in my laptop (WIndows 7 64 bit) and it shows up. Neither the port(s) on my computer are bad because if I plug in a USB drive, it shows up, too! I would highly appreciate if anyone of you could help me solve this issue.

Thank You.

If that is a external drive w/ a power adapter make sure the power adapter is directly connected to a wall outlet. If it is a passport you can use a power booster cable.

I have various data located only on this external HD and neither of my computers will recognize it. I have tried restarting PC and laptop with HD attached and still not finding it. It is an older model and was working find last time I backed up using it.

Whats the drive status under device manager and disk management?

clisk start/Rclick computer/click manage/comp management