Suddenly I cannot log-on to my PC. The laptop works normally. There is no longer a cursor governed by the mouse! There are no longer log-on entry boxes for my ID and Password, on switching on. New batteries in the wireless mouse and in the wireless keyboard....the keyboard is about 3yrs old and the mouse older. I am also unable to use my HP printer (currently wired but capable of wireless)....the HP Scan Doctor found nothing wrong. LENOVO PC, I have Google/Chrome as my main engine on the PC. Internet Explorer 10 I keep 'everything' updated. SKY router.