My friend's Windows 7 x64 ultimate machine recognizes some USB flash drives but not some other ones. The types of all are USB2 and also all drivers are installed (device manager). I don't know what is the problem. I also have done the works of here: http://www.techspot.com/community/topics/my-machine-doesnt-recognize-some-usb-flash-drives.202702/#post-1404832
And this is an image from that flash drive (silicon-Power 4g). Any idea how to solve he problem please?