HI, I'm having a problem with my mass storage devices. I updated my bios on my Asus z87 pro motherboard and since I did any of my usb sticks or WD My Passport wont open... PC says it tries to download drivers but can't. It sees the unlock disc for WD My Passport but wont let me open it and has the yellow exclamation mark by it in the device manager. As for the usb sticks.. they don't even show up even though they do in the bios page and they make a sound when you slot one in to a usb port.. so I don't think its the ports. especially as other items like flight yoke, pedals and mouse etc all work in the various usb ports.. its just the mass storage devices. I have looked at the files you suggested might not be there (as above) and all are. so bit lost as to what to do. Any ideas?