Today, I need some help figuring out an issue I am having. I have two USB 3.0 ports in the back of my computer that will not work; however, there are two other USB 3.0 ports in the back of my computer that do work for a total of two non-working and two working USB ports. I have tried to reinstall the chipset and USB 3.0 drivers (latest versions) for my Sabertooth Z77 motherboard, uninstalled the USB host controller in device manager, and have even checked to ensure that BIOS didn't have the ports disabled.
I have used these two ports on a regular basis, but they only stopped working today after I cleaned out my PC. An interesting thing to note is that the devices I plug in receive power from the non-working ports themselves, but show no signs of trying to connect. I have tried multiple USB devices unsuccessfully in both ports to solicit a connection, no luck. USB legacy support is on. Finally, I would like to note that when I go into BIOS under boot selection, I can see my USB flash drive as an option to boot to. The USB flash drive is currently in one of the non-working USB ports.
If anyone has any suggestions or ideas, I would greatly appreciate it.
The issue, as I continued to research the problem, ended up being with the registry. Simply deleting a few entries and restarting the computer fixed the problem for me, and now my devices are fully connecting.
http://support.microsoft.com/kb/925196 (This is for Windows XP, but it seems to work for Windows 7. Use at your own caution.)
Please note that using system restore/image is a solution you'll want to explore first.