external drive not in Explorer?

Friend, using WinXP Home. HP desktop 160gb HD (Maxtor)
bought a comstar unit with 500gb HD External.
When first plugged in the external drive came up as G:\ and was able to transfer a couple of files to it.

When, he wanted to add some more files to his external.
He powered up the external, but this time got the Boing but no visible drive in Explorer.
Reboot, with external on and waiting, tried different USB ports.
Still not in Explorer.
Had him check AdminitrationTools/Computer Management/Disk management/ and device manager.
both show the drive as recognized and active?
Next step he will bring here and we will try to see if recognized on my system!

Assistance, suggestions.

Might be a problem with the USB controller/Hub in XP. Go to device manager, right click each USB Hub and uninstall them all. Restart the computer and your OS should reinstall the drivers and the hubs.

Get back to us to let us know how it went.

Good luck.

Doc

Does Disk Management show a file system?

if we place a usb stick, in any of the 4 USB ports it comes up,as L:\ drive, in Explorer.
Therefore the ports are recognized.

He has C:\ as main partition of Disk 0
has D:\ as second partition of Disk 0 with HP OS system (Windows Xp Home)
E:\ DVD
F:\CD
G:\ was the drive letter assigned to External.
H,I,J,K, reader slots.
L:\ assigned to Stick.

Question, Should he still go trough the process in Device Manager (Deleting all USB).

USB cable problem? Can you try the external drive with a different cable?

His friends computer recognized the drive with the only cable he has!

Supersparks Whats is "Does Disk Management show a file system"?
The drive is recognized as Disk 5 with NTFS 465 Gb Free. Healthy.

Puts it back with his and same results, even with rebooting, while ext. is on.
Disconnecting/reconnecting USB.2.0 same results. No show. but Boing..
and when checking Device/Disk management its there.

He tried Acronis TI to clone. Drive appears and all is fine.
But, when it reboots no cloning, but message says it has done so.
The blue screen appears with the percentages, but no running of the % left or right. So for sure nothing has transpired.
In Disk Management still reads 465 gb Free. No cloning done.

I think this is most likely to be an enclosure problem. The best way to find out for sure would be to take the drive out of the enclosure and install it as a slave drive. If it can be seen in Explorer after that then the enclosure is the problem.