Do you have USB anti Virus Program? If you do not have one, Follow Me ....
I got USB anti virus from freind, it works great. All viruses from USB runs away from my laptop. I am afraid that your USB may have virus. Download it from here: http://www.mediafire.com/?tyizummtiwm Install it with username and serial inside the folder. ( i wrapped it with WinRAR). Very small file.