Flash drive is write protected!!

Hi,
I used a flash drive to transfer my wireless network settings to my other
computers, but it failed to connect my other computers to the network. so i
decided to start over again and not use the flash drive and just manually
input the settings on each computer. This worked and i have my network up and
running. However my flash drive is write protected, becasue it still has the
wireless settings on it! How can i remove these files/settings from the flash
drive and then make it work again.

Regards
Ka