Hi again, Pavlex4!
Is the USB flash drive encrypted by any chance? Have you tried plugging it in another computer and see how it will get recognized there?
When you right-click on the tab Disk 3 in Disk Management, what options are available?
I'd recommend you to try re-installing the USB drivers on your computer from the motherboard manufacturer's website or the Drivers Pack CD/DVD.
1. Click Start > Run (In Vista use the search box) type sysdm.cpl in the Open box, and click OK.
2. Click the Hardware tab and click the Device Manager button.
3. Expand Universal Serial Bus controllers.
4. Right-click every device under the Universal Serial Bus controllers node, and then click Uninstall to remove them one at a time.
5. Reboot the computer.
6. Once restarted reinstall the USB controllers.
Give it a try and let me know how it goes!
SuperSoph_WD