Starting a few days age, when I plug my USB drive into my computer, and try to access in through it's typical F:\ area, I just get an error prompt telling me to insert a disk into drive F:\. I can find a USB mass storage device under device manager, and it says it's working properly and driver is up to date. Vista SP1.

Any ideas?

The same happened to me a few years ago on my XP desktop on my sister's USB.
The USB drive had died.

Does it just not work on your computer or on any? Try it on another computer first.

Just another quick question about USB drives, lately whenever I plug mine into computer, when I double click it in My Computer, it asks me what I want to open it with, so I have to go to C:/Windows to find Explorer and use that to open it.

A couple things to check:

• Is autoplay/autorun disabled?
  
• Is the upnp service disabled?
  
• Are you using the usb ports on the front of the case?
  

From time to time, I'll get a message saying my USB device has stopped functioning. I think my aging nForce 680i might be part of the problem, and changing the device to another USB slot always works. I doubt that's your problem though.

No
No
I tried 8 different USB ports.

It worked on a friends laptop 2 days ago... It's a brand new drive so I doubt it, but I will try again tomorrow.

Go to my computer, go to properties of the drive, and then autoplay tab and change it however you wish. Also works for external harddrives (which is very nice because windows trying to scan and load hundreds of files for an autoplay attempt is quite annoying).

Just a personal opinion, I'd disable autoplay on the flashdrive and your hdd. Prevents all sorts of nasty viruses, such as FASEC. Or you could just hold shift for 15 seconds when inserting it.

@Syphon: Have you installed any drivers for a usb device recently? I remember when I hooked a printer up and then swapped it back out, that port wouldn't recognize any other devices until I got rid of the driver.

Format USB Drive and see if it detects it.

Erm, how would I format it when it can't detect it?

@Elvang, I reinstalled the driver a couple times.

It turns out I may have magnetised it... But that shouldn't have affected it? I tried it on the laptop, it didn't work. Loss of a 3 week old 16 GB flash drive = suck.

Well, if you're certain that it doesn't work you can put it in your freezer as a last option.

Ah, I had forgotten about that.

How long?

You said it worked on other systems, so try formatting it on that system.

And the freezer thing was always fun. An hour seemed to give me 2 hours worth of Playdium time.

I don't really remember, Sorry.
My guess is that only a few hours before drops of water form and actually freeze the USB for real

Reading, try it. I'm off to the freezer.

Make sure the usb ports are working with another device.
Uninstall all related drivers, restart. Wait a few minutes for startup to finish. Plug in drive and wait to see if it auto detects. If nothing, try switching to another port.
If not, try control panel > detect new hardware.
If not, unplug and install drivers manually. Plug back in and see if anything.
If not, try http://digital.ni.com/public.nsf/allkb/1D120A90884C25AF862573A700602459 or anything under google "force usb drive detection".

If none of that works try disk management. If your flash disk is listed then you may be able to repartition it and get it to work again but all information will probably be lost.