From what I can see , it will only format when you select how much space on the drive you choose to have as a " private folder " as you have this/these already you won't need to format .I have to add I have never used these types of drives before so am only going on what I have read in the relevant ,pdf .
Ashrich, thanks for your interest and my apologies for the delay in replying. However I have solved the problem I changed the compatability from Vista to XP and the password now comes up. I had forgotten that when I originally installed Vista I had to swap compatability for the flashdrive. I rcently had to reinstall Vista and forgot. DOH!