Mouse and keyboard input not working after windows 10 upgrade from windows 7.

Thank you, thank you, thank you!!!

You are absolutely correct. The issue with nonfunctioning keyboards and mouse at logon is due to a major conflict between Kaspersky and Win10 on somewhat older machines (a few years old). I just spoke with Kaspersky and they are getting a huge volume of calls with people experiencing all the issues reported in this thread. 

There is hope for anyone still pulling their hair out. Follow the steps at the thread below "exactly". I'm writing this to you from a computer that had been frozen at the logon screen for 4 days so I know it works.

If you have Kaspersky on a Win7 computer, DO NOT UPGRADE TO WIN10. If you have a computer with Win7 and Kaspersky and its working fine, just leave it alone. If you are locked out of your computer after upgrading to Win10 or downgrading from Win10 to Win7, you will need to remove Kaspersky using the directions below. Call Kaspersky tech line (its available at their website based on where you're calling from) if you need assistance. You will get a live person.

http://support.kaspersky.co.uk/general/products/10663#block5

Hi, Heatwave - you say you have checked and tried everything but I am gonna be really surprised if that includes the solution I posted on 2nd Nov a couple of pages up this thread. There is a link to a fix using Kaspersky rescue disk and editing the registry "offline" from the rescue environment.

What you describe is exactly what happened to the laptop I fixed. Give that a try!

The link again:

http://support.kaspersky.co.uk/general/products/10663

I'm desperate. I have an HP desktop running kaspersky with a Logitech wireless keyboard and mouse with win7. It was running fine but I figured it was time to upgrade to win10. I made the upgrade and at first it ran fine but after several days it began to run slow and freeze up. 

I decided to revert back to win7. It seemed to restore fine but when I got to the logon page the keyboard and mouse that previously worked fine were dead. Is this sabotage by MS?  I've done nothing wrong and followed all instructions for upgrading to win10 and downgrading back to win7. 

I've read this entire thread and tried every recommendation. None of them have worked and now I can no longer access anything on my computer. I've tried rebooting in Safeboot with no success. Does anyone have any solution? My kb and mouse work fine through the bios startup but once I get to the win7 logon my kb and mouse stop functioning. I've tried powering down in all types of configurations. I've tried a ps2 keyboard and mouse. I've tried a usb kb and mouse in addition to my my Logitech wireless kb and mouse that worked fine before this win10 catastrophe. I've tried using my my win7 repair disc but nothing seems to work. I cannot access anything inside win7 to make changes. 

Can someone please help me?

I spoke too soon. It doesn't work from a fresh startup (meaning powered all the way off then back on) but will work on a restart. I can however use the on screen KB to log in, then the keyboard works fine. Again, I think this is all in how Win 10 loads drivers--poorly.