I have a three year old dell inspron desktop running updated windows 8.1 64bit. Suddenly NONE of the input devices are working. I've tried several different wireless mice, and I've tried both a wired and wireless keyboard. NOTHING. I've tried using different ports (both on the computer on on my splitter) I've tried unhooking both devices, rebooting, then hooking them back up... looks like its loading drivers, makes noise, but still nothing. Tried rebooting with them installed. ARRRGGGHHH. Since I have no keyboard I can't do safe start (don't even know if that works with windows8 ). I do have a "repair disk" that I created when the computer was new.... tried rebooting with it in the drive.... didn't do anything other than restart the computer with the same non-functioning input devices. I hear my external hard drive working... so it must be doing something... so I guess its not all USB devices that are down. And the computer "dings" when I try to attach either to a usb port. I did install new logitech software last week, but it worked fine for several days, just quit working when it woke from sleep. I'd love to uninstall the logitech and go back with standard (functioning drivers), or do a system restore, but I can't do that since the mouse is not working. Any suggestions/help would be greatly appreciated. Thanks.