Keyboard, sometimes mouse doest work on W7 login screen, works bios& after login fine

[SultanGris]

Odd issue, been playing with computers since the 90s and never seen this happen. All of a sudden like my keyboard and sometimes my mouse are unresponsive at the windows 7 login screen. Sometimes the mouse works, sometimes it doesnt. If it doesnt work initially on power up it has worked every time so far after a reboot. Keyboard works just fine in the bios and just fine in windows after i use the onscreen keyboard to log in if the mouse is working but no response on the login screen. Capslock/numluck and any other button that should activate or change lights on the keyboard have zero effect when the keyboard is unresponsive.

Anyone ever seen anything like this? Ive just recently formatted/reinstalled a couple times without issue. Have been playing around with some virtual machine and vpn programs. Using avast antivirus this time around, used avg before, nothing else should really be different. Ive formatted hundreds of times and never seen this, pretty sure hardware is not the cause as it works fine before/after login screen. No strange new software that I can think of other than a vpn software program which ive only used in a virtual machine environment. Unless I somehow got a virus or malware that avast and malwarebytes cant detect Im kinda stumped, cant seem to figure this one out on my own, any thoughts? I spose the easy answer is just format again but I hate having a problem I cant solve.

I should mention i did try uninstalling avast as would be the first obvious step but it had no effect on the problem, it still occurs.

 

[SultanGris]

Well I kinda feel dumb now. As often happens when I post a plea for help I end up solving it myself and just looking like a dumb noob, ha!

No idea how or why this caused it but as I was dinking around trying different things as you do and I happened to notice an old Samsung Galaxy Note 2 cell phone with no sim card that I was playing with a while back was still powered on and connected to my PC via USB port. It had fallen out of visual range and I had totally forgotten about it as I often leave my pc powered on without a restart for a week or more. Unplugged it and restarted a few times and everything is working fine, plugged it in again and restarted a few times and it stopped the keyboard from working again so Im pretty sure its the cause. Anyone know why that would be? Im pretty sure Ive restarted my pc with various smartphones connected in the past with no issues, though maybe I havent or if I have they may have had working sim cards in them. Anyone have any thoughts or similar experiences with this strange behavior?