I have an Ativa 512mb

I have an Ativa 512mb flash drive and I have WinXP as my OS
when I put in my flash drive XP prompted me to chose an action to have my computer do when I put my drive in again and I accidentally chose the wrong one. I chose for it to read the files within the device which is a huge problem because it is password protected. So basically it's trying to open a password protected device without a password. And I can't chose to do anything else. Help please.