How Come Windows Can't See My USB Drive?

--Bloto, from the PC World Answer Line Forum

There may be several reasons why Windows turns a blind eye to your external drive. First, you should figure out if the problem is with that particular drive or port. Try plugging the drive into another USB port--preferably one on the other side of the computer. Some ports (usually the front ones on desktops) can be more finicky than others. Next, try the drive in another PC, or another drive in the same PC. These tests will tell you if you have a bad drive (which you can replace), a reasonable workaround (use another port), or a real problem.

If it's a real problem, try uninstalling and reinstalling the driver for that drive. USB storage drivers are very easy to install because they're built into the drives, themselves. Here's what to do:

1. Connect the USB drive.

2. If you're using XP, select Start, Programs, right-click My Computer, and select Properties. Click the Hardware tab, then the Device Manager button. For Vista, just click Start, type device manager, and press Enter.

3. You'll find the drive listed under 'Disk drives.'

4. Right-click the drive and select Uninstall. Confirm by clicking OK.

5. Now unplug the USB drive, then plug it in again. The drivers will reinstall automatically.

Vista has its own USB problem that keeps it from recognizing drives under certain conditions--for instance, if your PC has been in sleep or hibernation mode. Microsoft released a patch last October: update number KB941600. Even if your PC is set to receive automatic updates, it may not have received that one.

You can read more about this patch at Microsoft's Knowledge Base. And you can download the 32-bit version at Microsoft's download site. Unfortunately, this is one of those updates that requires validation (don't we all), so it forces you to accept Windows Genuine Advantage if you haven't already installed that update.

If, when you try to install the update, it tells you that it "does not apply to your system," that means you already have the update installed on your system.

My thanks to the many people at PC World's Answer Line Forum for the answers they offered when bloto first posted this question.