hello, can you try to replicate this behaviour when you launch firefox in safe mode once? if not, maybe an addon is interfering here...

Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

Thanks MP, but that didn't work. I even removed and rejoined PC to domain & removed and recreated the user's profile. Even before I recreated the user's profile I tested the behavior with the local admin account and same thing was occurring. Really crazy!

Any other ideas...anyone?

you could also run a full scan of the system with different security tools like the free version of malwarebytes, microsoft safety scanner or kaspersky security scan.

Try this out:

1) Click Start 2) Control Panel 3) Printers and Other Hardware 4) Keyboard 5) In the Keyboard Properties window, click Hardware 6) Click Properties 7) Click Driver 8) Click Uninstall, click OK 9) Restart your Computer

The steps could vary slightly from OS to OS. Once the computer has been rebooted, your keyboard will work again, hopefully even the Ctrl part. Give it a go and get back to us!

It is possible that some of the status keys have the wrong state and Firefox sees them as still pressed.

Try to press all the status keys (Shift, Ctrl, Alt) a few times to see if that helps to recover from this if it happens again.

You can also try to reboot the computer.

Hi Matt,

Thanks for the suggestion, but there's no option to uninstall a driver. It's a MS Ergonomic 4000 keyboard and it just shows up as an HID compliant device. I tried uninstalling the Microsoft Mouse & Keyboard Control Center, but that didn't help either.

I've also pressed the keys numerous times (at one point it asked me if I wanted to enable 'Sticky Keys' which I didn't). Rebooted too. Even deleted the user profile, removed the PC from the domain, rejoined it to the domain, logged in as the user, and restored a previously backed up Transfer Wizard profile. And I checked while logged on as the local Admin and got the same weirdness.

Did you try another keyboard in case there are hardware or driver issues?

cor-el: yup...tried a different keyboard too. Had a problem previously when we were using a bluetooth headset and wireless mouse both from Logitech, but the headset is out of the picture now. I'll try swapping out the wireless mouse for a usb mouse, but I don't see how that could be the problem.

Also ran a fun scan with Symantec Endpoint Protection: it found one tracking cookie

Thanks