My Dell N7110 installed Win 10 free update nicely. Had some minor quirks but fixed and had to install updated software for HP products. Problem arose, when during Anniversary update, my mouse started connect/disconnect. Traced it to a bad wire at the mouse. Bought a new Microsoft wireless mouse. Plugged it in-works. But--on "Retarts" for installation of software, and on updates, at Restart black screen got message "unable to find operating system". Hard boot-started and loaded flawlessly. Tried the "restart" from the power icon-"can't find operating system". After three days of scouring the net, pulled the "dongle" out after restart screen opened, restarted normally. Went into "Bluetooth controls" turned off "Bluetooth" and tried restart, worked normally even with dongle in. And, the wireless mouse works fine. I think having the Bluetooth on and having a Bluetooth transmitter, combined to mix up the computers bios. Is there a fix for this, so I can leave the Bluetooth on for my other devices and still use the wireless mouse? For the moment, I went out and bought a new "old school" wired USB mouse and there are no issues with the Bluetooth on and the wired mouse with "restarts".