see first back up all the files u want then download HP USB Disk Storage Format Tool from this site: http://en.kioskea.net/download/done/download-127-hp-usb-disk-storage-format-tool
now reformat it in FAT32 format
To optimize your USB drive for performance:
Right click on the USB drive and select properties
Select the Hardware tab
Under All Disk Drives, highlight your USB drive and select Properties
Select the Policies tab and select Optimize for performance.
Press OK twice, and your transfer speeds should increase dramatically
Note that when your drive is optimized for performance you’ll need to use the Safely Remove Hardware icon in the taskbar to eject the drive – otherwise you’ll risk corrupting your data by just removing the drive from the port.
Now it will definitely work!!!
Jibin 'The underdog' Joseph, June 2010