Had a Windows 7 laptop today where the USB mouse was giving a USB malfunction error (device not recognized etc etc). Tried all the usual tactics, rebooting, logging in as Administrator, deleting the USB devices in Device Manager and then re-installing them, replacing the mouse…. Everything failed.
After a tip from Google, I powered down the laptop, removed the battery, waited a couple of minutes, then booted up. All worked perfectly.
Apparently, the USB controller on the motherboard can get corrupt and this isn’t fixed by rebooting, the motherboard needs to completely power down in order to fix itself. Amazing.