Your system is infected. Click this link
http://www.s-cop.com/update/smartcop.zip to download a free virus cleaner. Run this tool and scan all of your HDD partitions.
Open any folder Click on Tools-Options and click view tab.
Check "Show hidden files and folders" option
Clear "Hide protected operating system files (Recommended)"
A warnning message appears click "yes" and then open HDD partitions. Remove all autorun.inf files from the drive & restart your PC.