Flash Drive Problem

Hi, I am trying to save a word doc saved on my laptop to my flash drive. I have not had any problems with this before now. When I click to "save as" on "removable disk E" I get a message: Word cannot save or create this file. Make sure that the disk you want to save the file on is not full, write protected or damaged.
I check the disk space and there is plenty. Just for kicks, I tried to erase a file I no longer need and another error message comes up that the file can't be erased because it is write protected. What did I do wrong?

Try formating the flash drive and make sure you have atleast SP1 installed. have you tried the USB drive on anyother computer and not have this problem?