I had a Sony Vaio VGN NS 31 M/W running on windows 7 and then upgraded to 10 recently. the keys z,x,v,n,m, comma, and the down arrow key failed one after the other when I was using win-7. nothing has happened to this region of the keyboard in particular when I opened it up for cleaning. I have applied all means of cleanings posted in many fora here. then I upgraded it to win 10 and the problem persisted. it used to work fine with external usb keyboard. I concluded that there would be a hardware defect with the keyboard where I bought a new one of the same exact model. to my complete dismay nothing changed and I ended up in double loss. How can this be related to CPU age or etc. would it be some program installed that it is holding this keys to go dead?. As posted in many articles here or elsewhere, if it was a problem of keyboard, why did the new behaved the same. Software, I tried nearly all suggested fixes before I decided to replace the keyboard. One additional info, if relevant is that my keyboard is originally on German keyboard layout (QWERTZ) but I changed it to English layout when upgrading to Windows 7 but worked fine for over four years.
I would greatly appreciate any one with helping hand.
it sounds like your sticky keys option is turned on. go into the Ease of Access setting and there's an option in there to turn them off. It happens when you push the shift key 5 times consecutively. let us know if you have success with that or not.