ASWKBD.sys is buggy. I have (had) an intermittent problem where the KB on my new Acer Aspire V7 (Win 8.1) would not work - with the exception of the Fn+F9 and the Vol and Brightness controls. After a LOT of searching -- I found the problem/solution in another forum and I am including a synopsis here: "... Use regedit.exe to search for "aswKbd" and delete the string "aswKbd" ONLY and nothing else!!! After that, use Unlocker to rename aswkbd.sys in the windows/system folder to aswkbd.old. Reboot. Problem solved.