How to delete write protected from pen drive

Formatting it in DOS may help....
Open the DOS prompt (Start >> Run >> cmd)
Type:
FORMAT X: /FS:FAT32 /Q /V pen Drive
This will reformat the Pen drive, using the FAT32 file system, and label the drivePenDrive. Replace X: with the actual drive letter of your Pen Drive. For more help on this command, type:
FORMAT /?at the command prompt.


If you want to unhide files from the pen drive(if any)
Open a dos prompt (Start >> Run >> cmd) and type:
attrib -r -h -s ./s x:\*.*
This will change the attributes of all of the files on the pen drive. Readonly, hidden, andsystem attributes will be removed. Replace the X: with your pen drive's drive letter. Now you will be able to see them in Explorer, and delete them, without formatting anything.

If your warranty period is not expired, it is better to replace it with new one.