External HD/ USB problem

[Riley50]

Hi - I am running XP and have 3 external hard drives for backup and storage. The 500GB discs spin up and may or may not be 'seen' (ding dong!) by my PC. If they are seen then it is only as a USB storage device but the drive letter is not seen and it is not possible to access them. I have tried direct plug ins, also powered and unpowered USB hubs to no avail. Needless to say disc management does not see them either. Device Manager say s the devices are working properly...
Occasionally they work!!@@!
Ideas would be appreciated.
TKIA

 

[raybay]

Does this external drive has its own power supply that plugs into the wall, or is it trying to feed off the computer power...

Also brands and models... EIDE/ATA or SATA?
It is always useful to post the brand, model, and age of all components when you get into such a problem.

 

[Riley50]

Hi - all external drives have their own power supplies. All drives are less than a year old and they have worked occasionally, so are formatted and contain data. I have tried every permutaion of plugging in and hub I can think of.
cheers

 

[Riley50]

What's most irritating is that I have the little drive and green arrow in the launch bar. If I start safely remove then it shows 'USB Mass Storage Device' which is apparently 'working properly!!