Keyboards no longer work on Windows 7, but the function keys work

Hi everyone, this is a really puzzling problem that I've never seen before or even heard of.

Basically, my battery backup for my PC has recently conked out and there was a temporary power outage in my building. So the battery backup didn't kick in (my fault for not replacing it) and the PC was shut down instantly. When I booted it back up, the USB wired keyboard was no longer working, but everything else was fine.

To debug this issue, I've tried all of the following:

* Tried the USB in a different port
* Tried the same keyboard on my mac laptop, it works fine, so the keyboard is not at fault.
* Tried two other keyboards (one USB wire, one USB wireless) on the PC, neither of them works on this PC. Both these other keyboards work fine on my Mac and on another PC.
* Noticed yellow exclamation points in the Device Manager under keyboards, indicating a "code 19" error. I followed these instructions. The error went away but the keyboard problem did not.
* Did a malware check.
* Tried booting in safe mode, still same problem. I'm able to boot into safe mode with F8 because the keyboard works fine during boot up. Only at the login screen do the lights go out and it stops working.
* I tried disabling the drivers, uninstalling the drivers, updating the drivers, and restarting.
* Tried rolling my PC back to a restore point. System Restore keeps telling me that my anti virus program is preventing access to some files so the restore point doesn't seem to go through.
* Tried System Restore in safe mode, same result. Tried uninstalling anti-virus and disabling Windows Firewall. I get the same error on attempting to restore the system. This is another issue altogether but just mentioning that I tried it.

Some other things to note:

* The device manager doesn't list a specific keyboard device to match the keyboard itself (It's an "Elephant" brand keyboard), it only lists "HID Keyboard Device" and "Wireless Keyboard Filter Device", both of which are listed as "working properly". I don't know if that's a problem, or if that's common to not list the keyboard itself.
* The whole thing seems to have been caused by the power outage so it could be a hardware issue. But the fact that this isn't indicated in Device Manager is puzzling (but I'm not a hardware expert).
* The function key combos work fine. So I can do Fn-Home to open Windows calculator, for example.

If anyone has any suggestions on what to try next, I'd appreciate it! Thank you.

Do you still has a yellow alert on device manager?
On the power outage some files could have been damaged.
Don't think it's a hardware issue because the keyboard works fine during boot up

Boot from the win 7 installation disk, go to repair, open a cmd window and type:
- chkdsk c: /f to do a disk check
- sfc /scannow to do a system file check.

Megahertz07 said:

Do you still has a yellow alert on device manager?
On the power outage some files could have been damaged.
Don't think it's a hardware issue because the keyboard works fine during boot up

Boot from the win 7 installation disk, go to repair, open a cmd window and type:
- chkdsk c: /f to do a disk check
- sfc /scannow to do a system file check.

Thanks for the response. No, there is no error in the DM anymore. That went away with the fix I linked to. I don't recall having an installation disk, but I do have a legitimate version of the OS. I'll have to check, but I bought the PC in 2010 so it's been awhile. I guess I should be happy it's lasted this long without any major issues.

Anyhow, thanks, I'll try what you said. I'm actually trying first to do a disk check on boot up without the installation disk, I don't know if that will help to at least find the problem, but I suppose it can't hurt.

Update:

I was able to boot from an installation disk and ran both chkdsk and sfc. The chkdsk command finished but had some kind of a log error. From what I could see, it ran fine but had problems with a log file, which I don't think would be a problem with the scan. The sfc command ran fine, with no problems found.

So I'm somewhat back at square one.

If anyone has any further ideas, that would be great. Thanks.

It must be a corrupted USB driver.
On Device Manager, try to uninstall all USB drivers and reboot.

Megahertz07 said:

It must be a corrupted USB driver.
On Device Manager, try to uninstall all USB drivers and reboot.

Would there not be an indication in Device Manager that drivers were corrupt? Also, when you say "all" drivers, you mean everything? Or just the keyboard ones? Thanks for the response.

Megahertz07 said:

It must be a corrupted USB driver.
On Device Manager, try to uninstall all USB drivers and reboot.

Didn't hear back from you but I tried removing many of the USB devices in Device Manager. I don't think I removed everything, because some of them seemed very unrelated. Anyways, eventually my mouse stopped working as I was uninstalling stuff, so I had to manually restart the machine. The drivers were reinstalled on boot-up.

Basically, nothing's changed. Keyboards still don't work, while everything else works fine.

Sorry Louis, can't think anything else to do, only a factory restore.
Factory restore will format your disk so backup your data files on an external disk.
For the updates: MS releases SP2 for Windows 7 - Windows 7 Help Forums

May be someone else has an idea of what is going on.

Megahertz07 said:

Sorry Louis, can't think anything else to do, only a factory restore.
Factory restore will format your disk so backup your data files on an external disk.
For the updates: MS releases SP2 for Windows 7 - Windows 7 Help Forums

May be someone else has an idea of what is going on.

Thanks for trying to help. I took it in to a local repair shop to see if they could at least diagnose the problem. They couldn't really figure it out either and said they only way was to reinstall Windows or upgrade to W10. They said the hard drive is in weak shape so it wouldn't be worth it trying to install Win10, so I'm just going to backup my data and move on to a new system. I have laptops I'm using in the meantime, and I've just ordered a new computer.

7 year old computer that I've used just about every day, so I guess i should be happy it lasted this long.

Most of us at this forum think that Win 10 is just a better Win 8. Win 7 is still the best.

I would say you have a good computer with a software issue.
If you do a factory restore it will work as new.
HP Notebook PCs - Using System Recovery, Factory Reset and Minimized Image Recovery Options | HP® Customer Support

And if you want to spend some money, buy a 128 G SSD for Win and programs and use the HDD for data.
You'll have the speed of a SSD and the space of a HDD (for only US$ 50)