Solution for USB flash drive not to be displayed

A few days ago, when I was repairing a computer for someone else, I put my USB flash drive behind the computer. The computer had recognized the USB flash drive, but I couldn't see the drive letter when I turned on my computer. Go to disk management in "Administrative Tools" (enter diskmgmt. MSC in "run" and press Enter). You can see that the disk is not assigned a drive letter. Manually assign a drive letter G, but open "my computer", there is still no USB drive letter. Enter G: \ in the address bar, and the system prompts that the file: // G:/cannot be found. If you format the USB flash disk in disk management, the system prompts that the disk cannot be formatted and the volume is not enabled. If you right-click the allocated g disk in disk management and select resource management, the system prompts that the G: \ cannot be found :\. However, in the Windows Console (command prompt, Enter cmd in "run" and press Enter), you can enter the USB flash drive and perform normal operations (copy, delete, and open files ). The strange thing is that you can see the drive letter when you plug in the mobile hard disk.
Final Solution:
Go to the system directory c: \ windows \ system32 \ drivers to check whether there is a "sptd. sys" file. Delete it and restart it. Solve the problem! Note: This "sptd. sys" is not provided by Microsoft Windows.
Other possible causes:
1. There is a ing network drive in the system, so the drive letter cannot be allocated to the USB flash drive.
Solution:Disconnect the mapped network drive.
2. The drive letter is hidden.
Solution:Go to the Registration Table (regedit.exe) and go to the HEKY-CURRENT-USER \ Software \ Microsoft \ Windows \ CurrentVersion \ Policies \ Explorer branch. Find the key value "nodrives" in the path and delete it. Log out and log on again. (Not the NoDriveTypeAutoRun key value ).
3. USB flash drive problems.
Solution:Format the USB flash drive again. It is best to perform low-level formatting and find a USB flash drive tool on the Internet.
4. If it doesn't work, the last trick is to reinstall Windows XP!