I had given my external hard disk to a friend whose computer was infected. When I got back my disk, I found that my disk was infected by a virus and it had changed all of my folders to .scr files and they were write-protected. Since I had Avast installed on my computer, it had detected the virus and it recommended me to run a boot time scan to fix it. So I ran a boot time scan and identified some viruses as Win32:SaliCode and Win32:EB-VIK. It repaired some files and the others, it moved to chest. But when the scan was completed, I found that all of my data on the hard disk was gone. But the strange things was that, my disk space was still as if I had all of my files. Please fix this problem Avast. I have very important files on that hard disk.