Connecting external HDD hangs windows.

[majorsparky]

I have two IDE HDDs each of which is installed in a caddy that connects to the PC via a USB port. I use these external HDDs to back up the two internal HDDs (one for windows xp and one for my document files).

Recently, windows stopped responding (would hang) when I connected an external HDD and switched it on. I get the same result whichever of the two external HDDs I connect. I have also tried booting the PC with the HDDs connected and switched on, but then windows hangs before it finishes loading.

The windows xp device manager shows no yellow flags on any device.

One other thing, when I connect any of the external HDDs to another PCs USB ports, everything works fine.

Any suggestions as to what is the likely cause of this would be appreciated.

Major Sparky.

[glc]

Could we get some more specs, please?

[majorsparky]

glc,

The PC runs Windows XP, has an AMD Athlon 2800+ processor and two Maxtor Diamondmax 10, 165Gb drives inside. The external caddy mounted drives also have the same IDE HDDs inside, each caddy having a USB2 port for connecting to the PC. I also have an HP USB color printer installed that works fine. There are 6 USB ports on the PC (the problem of Windows hanging occurs whichever USB port I use) and the USB controllers (SiS 7001 PCI to USB Open Host Controller, USB Printing Support, and USB Root Hub) all seem to be functioning O.K.

As I said, this problem has started to occur only recently. I have used the external drives to backup the internal ones for many months.

The internal drives have lettered A: to F:. The two internal drives being C: and D: and the two optical drives being E: and F:. Could it be that the PC is configured to recognise drive letters only up to F: (and not Z)? I'm clutching at straws, as we say over here).

Major Sparky.

[glc]

I doubt that would do it, but you can download TweakUI and install it and check the My Computer tab to check that theory. I would think the device should still mount but not be assigned a drive letter if that were the case.

Have you tried it in safe mode? I'm clutching at straws too. My initial thought was your USB controller does not like the IDE to USB converter card in your housing, but why would it work then stop working? This is why I asked for specs - and I see you have a SiS chipset. Do you have any idea who makes the converter in your housings?

Something else to try - disconnect all USB devices and uninstall all USB controllers and root hubs - then reboot and let them reinstall.

Did you recently add any new hardware to the PC like a sound card or anything?

EDIT: From another thread - do you have anything like Daemon Tools that installs virtual drives?

[majorsparky]

glc,

- Tried safe mode but with the same result; windows hangs.
- Tried uninstalling all USB controllers and root hubs and then rebooting to re-install them; then connecting the external HDD drive, and.....Windows hangs.
- Installed Tweakui.exe and verified that drive letters to Z are allocated.
- Have not installed Daemon Tools.
- Tried connecting digital camera to USB port and powering it up, and software works fine.

But one thing you mentioned... Since I last used the external HDD, I have changed out a video card in the PC. It used to be a Radeon 9600 XP(?) AGP card with 256Mb ram. I used that card in another PC and replaced it with a Radeon 9000 Pro AGP card with 128Mb ram.

Why should that cause my problem; and what do you suggest I do - short of replacing it with the original one?

major sparky.

[glc]

Replace it for troubleshooting purposes - I've seen stranger things happen.