Hi phZE. My name is Ivan, and I am a Microsoft Expert. I'd be more than happy to assist you. I'm so sorry that you are experiencing this issue. Don't worry, I'll do everything I can to help you.
That sounds frustrating, Grant! It seems you've tried a good number of troubleshooting steps already for your Sculpt Ergonomic keyboard. Here are a few more things to try and isolate the problem:
Isolating the Keyboard:
Check the Dongle Connection: Try plugging the dongle directly into a different USB port on your laptop, preferably a USB 2.0 port if available (some users report issues with USB 3.0 ports).
Test on Another Device: As you mentioned you tried another device, double-check that the keyboard truly doesn't work on another computer. This will help determine if the issue lies with the keyboard itself or your laptop.
Ruling Out Software Issues:
Windows Troubleshoot: Windows 11 offers a built-in hardware troubleshooter. Go to Settings > System > Troubleshoot > Other troubleshooters > Keyboard. Run the troubleshooter and see if it detects any problems.
Checking Hardware:
Look for Physical Damage: While unlikely, do a visual inspection of the keyboard for any physical damage to the USB connector or obvious signs of malfunction.
Additional Tips:
Battery Check: Though you mentioned changing batteries, ensure you're using the correct battery type (usually AA) and that they're inserted with the proper polarity (+/-).
By trying these additional steps, you should be able to pinpoint the cause of the keyboard malfunction. Hopefully, it's a simple fix like a faulty USB port or a software glitch.