I have done searches and read through many USB related threads. Found nothing related to my problem.
I use 2 PCs daily. The notebook runs on Win XP and the desktop (7 month old from purchase) runs on Vista Home Premium.
Several USB devices (desk-top hard drives, SD cards, digital camera etc) functioned normally previous are no longer recognized by the Vista PC now. All these devices still work with the XP notebook. I checked all the usual suspects to no avail, such as loose cables, power-on-off and so forth. I suspect that it might be due to corrupted device driver. Worth noting is that I have one external USB hard drive (the only one) still works with the Vista. This blows the bad driver theory out the window, no?
The 3 external hard drives (one works and 2 don’t with Vista; all work with XP) that I use daily, all are from Iomega. Iomega claims that it does not have any driver for download since it depends on the OS to supply.
Also note that I have at least 6 available USB ports on the Vista PC and LCD Monitor combined. I had tried switching ports. Results same.
Appreciate any help to get these devices up and running again. Thanks.

In your Windows directory, head into the INF directory and delete (or rename) the infcache.1 file. It's probably a corrupted driver database.

I could have sworn we had a thread on the exact same thing a few months ago, but the crappy FT search is clueless about it.

FWIW; the topic is also covered on some other sites:

http://www.l.google.com/search?q=vis...GGL_en___US208

Good luck!

Thanks for the link. I will check it out later and report back my result. Thanks again.

Let's say I go ahead and delete suspect file, should I re-install it? If so, where would I find it? (sorry, I am real techno challenged).
Meanwhile, I will try to search for that old thread again. Thanks.

No, you just remove it. It's a cache, so windows will rebuild it when it needs to.

http://tim.mackey.ie/VistaDriverProb...HardDrive.aspx

-David

Like LIH Prem says; just delete (or rename it). Next time Windows detects new hardware it will generate a new database file.

What happened is that the driver database became corrupted (it's happened to me too). It's a nasty bug, and one that doesn't seem too well documented.

As usual, Microsoft seemed unaware of it at the time.

LIH Prem and ScottC,
Thank you both for the heads-up.
This link is very helpful. I actually understood most of what it said!
I followed the instruction closely from this link and deleted the INFCACHE.1 file. Rebooted computer. Same problem still there
After reboot, I checked for the above file, it was NOT in c:\windows\inf
I tried different drives at different USB ports (and repeatedly reboot) yielded same disappointing result. Any additional thoughts?

All the devices that you've described are storage drives of some sort. It sounds to me like there may be issues with the disk management services. Can you see the devices in Device Manager? If you're sure you've found the correct ones it is safe to delete them and let Windows re-detect the devices. If you aren't careful, however, you might delete the wrong drive, which would be bad.

There was one other thing I did when I had the problem, but I can't remember what it was

I'll try using Google to search FT because I'm sure it was here at one point...

You aren't seeing it possibly because it's a hidden file. If you follow these directions, you need to add something new to get it to rebuild the cache.

http://www.texxors.com/2007/05/09/ho...-a-new-device/

-David

Thanks for weighing in. I did check the Device Manager. All I found was what appeard to be generic names only; which when clicked on, it said empty.
Thanks for warning me to be careful when deleting a device. Just curious what is the "down side"? Already my system does not seem to detect NEW HARDWARE, can it get worse? Well I hate to think further. Already frustrated with this.

From the google searches, I read quite a bit just to educate myself to the nature of the problem and seek for solutions. It appears there are LOTS of people have similar problem like mine. Why Microsoft does not come with a fix?

In trying to fix this problem (deleting the INFCACHE.1 file), I had to grant permission the user group (in fact this computer is used only by me); resulting in a slightly different look-and-feel on my screen background (now all black with icon). Before, the background is a picture. How do I switch back to "admin" and get my picture to appear again on the screen? Thanks again.

Thank you for this link. I printed out the content of this link and will try it later this evening, and report back result.
I get used to my XP and am foreign to lingo like "administrator" vs "user-group" etc. Since I don't have anyone else except myself using this computer, can I get rid of user-group? Sorry for diverging from OP.

Thank you everyone for weighing in to help. I have done a number of things by following various suggestions here and elsewhere, and don't know which one did the trick. Now, I am happy to report that my system finally recognizes every USB device that I plugged in. The last thing I did was to install the SP1 update as was alerted by this thread
http://www.flyertalk.com/forum/showthread.php?t=802723

Thanks again, everyone. ^