Dell Bluetooth Keyboard stopped working

Try uninstalling it in Device Manager. Reboot and let Windows rediscover it. 

Search for the error message--lots of hits about this including hardware failure.

https://support.microsoft.com/en-us/kb/811798 relates to Window 7, and my tablet is running 8.1

I did try "If the link is not reestablished, use Control Panel to remove the device, and then try to add the device again," and it did not work. (Actually, I removed the driver and let Windows re-discover the device.)

The second link is for XP. 

I did what the third link said, and it did not work.

"

Put the Dell Bluetooth Keyboard in Discovery Mode

1. Starting with the Bluetooth device off, press the power switch located on the bottom of the keyboard.
2. Find and press the button located underneath the keyboard on the upper-left side.
   The Bluetooth LED on the top of the keyboard blinks when it is in discovery mode and is off when the keyboard is not in discovery mode."

None of what you posted worked.

Should I try a new keyboard? If I have to buy one, though, I will have to write the product I have a poor recommendation at Amazon and elsewhere. I generally expect things I buy to last more than a year or so before they stop working.

Your post doesn't seem to list the model or where you purchased it.  Could you provide more details about the product and the device you are pairing it with?  Thanks.

Regards,
Robert

It's a Dell tablet keyboard, to go with a Dell Venue.

However, I was actually able to pair it with my tablet yesterday (after I bought a larger Logitech keyboard to determine whether the tablet was the problem--it worked as well).