Request for troubleshoot-help: External Keyboard does not work anymore on Laptop

[dmark_one]

Hi folks
Ok, here's the weird thing: A mate of mine has a Lenovo Thinkpad T520 Laptop and since today his external wireless-Keyboard (Logitech K340) does not work anymore. The internal Laptop-Keyboard works.
The interesting thing is: He can enter his user/pass in the Win10 login screen and as soon as the desktop is built up the computer does not register inputs from the external keyboard anymore. The batteries of the keyboard are ok.

I already looked up on-line for some trouble-shoot advices and so far I already did the following:
- Tested another standard working USB-keyboard, no luck.
- Uninstalled and reinstalled both, the
> HID Keyboard Device
> Standard PS/2 Keyboard
from the device manager, restarted the computer, no luck.
- The USB ports are working otherwise; other USB devices are being recognized with no issues.
- Followed the steps as per https://www.drivereasy.com/knowledge/keyboard-not-working-on-windows-10-solved/ (without installing that 3rd party software), no luck either.
- Investigated into the issue of KB4074588 being the potential culprit as mentioned on the same page in the user comments and as referring to https://www.computerworld.com/article/3256218/microsoft-windows/buggy-win10-1709-cumulative-update-kb-4074588-redlining-bluescreening-borking-usb.html - this 'KB' is not installed on my mate's laptop to begin with.
- I removed and re-registerd the wireless keyboard with Logitech's "Unifying" application. The keyboard can be registerd again after removing it, however, the keystrokes are still not being registered.
- Last but not least, I did a system restore to a point where the keyboard was still working. Alas, the sytem restore failed with some 0x8007000x error, so no luck there either.

I'm getting at my wit's end here; currently I don't have any trick up my sleeves anymore.
If anyone could help me out and give me tipps and tricks that would be very much appreciated.

Thanks a lot.

 

[Kissmyne]

Did your friend accidentally turn on Filter Keys(or other Ease of Access related stuff) on their profile? If the keyboard works fine logging in, then the issue is likely a setting tied to the user profile such as the Ease of Access settings.

 

[dmark_one]

Did your friend accidentally turn on Filter Keys(or other Ease of Access related stuff) on their profile? If the keyboard works fine logging in, then the issue is likely a setting tied to the user profile such as the Ease of Access settings.

Hi, thanks for your contribution. I actually did indeed check these Ease of Access related stuff (I forgot to mention this in my initial post) and there everything was turned off. So alas no luck from that side either.

 

[gosubuilder]

look and check if setpoint is installed. if it is installed, uninstall it. then go d/l the latest setpoint software at logitech site, click here

see if that fixes it.

on a side note are you using the latest unifying software for this k340 keyboard, try d/l the latest unifying software here

 

[dmark_one]

Ok, eventually we found out what it was. It turned out that at my mate's company the administrator of the server-side driven Gdata antivirus activated some "do not allow untrusted USB devices to work" (or something along these lines). Thus, the Gdata client on my mate's computer refused to have the external keyboard working. Anyhow, the Gdata Administrator removed this "over-caucious" setting and - hey presto - the external wireless USB keyboard is working again.
Anyhow, thanks to all who contributed in attempting to help to this issue.