Some times your USB thumb drive or pen drive may face this weired problem, although the drive seems normal and is being detected by the OS, yet it shows the drive is write protected when you try to put some data on it. It can be because of physical errors in the drive or may be because of just some misconfiguration.
Common errors are:
Here are few tips you can follow when you face such situations:
-run “regedit” command
-Double click at “Write Protect”
-Change the value to “0”
HP Drive Key Boot Utility Method:
Download and Install HP Drive Key Boot Utility : http://snipurl.com/hpbootutil
It should work for most brands of flash drives.
Also check if your drive has write protect notch some where, toggle it then try to format it again.
I hope this would solve your problem.
If both of the above solutions didn’t work for your drive, then you can try the following:
Warning: Low Level format will completly distroy any data on drive, So take backup from the drive before using this tip.