This is the second time today I've seen you suggest reinstalling the operating system without exhausting the other options first. Reinstalling the operating system is what you do when you can't get anything else to work, we have not reached that point. I don't know if you just don't know of anything else to suggest or if you just give want to take the easy way out.
I don't see you suggesting anything else....if you can think of something better then put up or shut up.
I see no value whatsoever wasting time on grasping at straws doing piddly little tweaks....or using an endless supply of 3rd party software to scan for this or look for that.
Let's look at the facts of the case, shall we?
- Input devices work fine during POST but before OS Boot, but post-OS boot they don't work (HINT: This ALONE is a huge clue that points to Windows being the issue)
- Since Input devices don't work in Windows, all troubleshooting within Windows is out the door because it's impossible to do. So, even if it was a case of the drivers issue, they can't be reinstalled because no input devices will work. So, anything you could do within Windows is out. HINT: Since nothing can be done in Windows, it's impossible for the user to do as you suggested and type in devmgmt.msc to get to Device Manager. The keyboard is part of the problem, so that's not going to work, now is it?
- It's still doing the same thing in Safe Mode. Since we know Windows includes USB drivers pre-installed, and that Safe Mode is only loaded with the most basic drivers (of which USB drivers are anyway) it again makes sense.
What else is left to do? Nothing, except to do as I suggested and reinstall windows then swap out the motherboard if that doesn't work.
You call it the "easy way out," I call it fixing the problem ASAP.
As I posted elsewhere and the mods thoughtlessly deleted, if you're fixing someone else's computer do you think that person would rather be billed for 7 hours of your time screwing around with stuff that MIGHT solve the issue or 3 or 4 hours of something that is almost 100% DEFINITELY sure to solve the issue.
Maybe instead of whining about my posts you should come up with something better if you think my way is so bad.