Microsoft Mouse and Keyboard Center doesn't recognize Sculpt Comfort Keyboard (Windows 8.1 x64)

It's one of their new, top of the line keyboards also; that is what makes me angry.

Did you follow the installation instructions to the letter? I do not know if it still is the case, but originally installation required installing the software and drivers first, using your old keyboard and mouse hardware, and rebooting before plugging in the USB device.

Please post screenshots of both your Device manager and Microsoft Mouse and Keyboard Center, as above.  This might help to determine what went wrong.  If you plugged in the USB device before installing the drivers and Mouse and Keyboard Center, this potentially could be the source of your troubles.  Also, make sure you are an administrative user when connecting the hardware.

Have just had one delivered today and same problem. (Win8.1). The only paper instructions showed pictures of activating the batteries, plugin the transmitter and off we go. No mention of installing drivers before inserting transmitter. 

As noted earlier, the Desktop & Mouse Center do not appear to support this model. http://www.microsoft.com/hardware/en-us/help/windows-8/troubleshooting/mouse/supported-devices

I also have an Arc mouse which is the only device showing.

Is this likely to be fixed, or have I bought a dud?

Have just had one delivered today and same problem. (Win8.1). The only paper instructions showed pictures of activating the batteries, plugin the transmitter and off we go. No mention of installing drivers before inserting transmitter. 

As noted earlier, the Desktop & Mouse Center do not appear to support this model. http://www.microsoft.com/hardware/en-us/help/windows-8/troubleshooting/mouse/supported-devices

I also have an Arc mouse which is the only device showing.

Is this likely to be fixed, or have I bought a dud?

Interesting.  The instructions that came with my hardware had a picture of a CD with an arrow pointing to a computer, between activating the batteries and plugging in the transmitter.  In the written instructions it was mentioned that the drivers had to be installed first with the previous keyboard and mouse installed before plugging in the new and removing the old hardware.

One would think that if the link to the hardware offers the software, that the hardware would be supported.  Please post screenshots of Device Manager with Human Interface Devices, Keyboards, and Mice and other pointing devices categories expanded.  Please also provide a screenshot of Microsoft Mouse and Keyboard Center open to the keyboard section.  See my examples above.

Have you checked Windows update for optional hardware and software downloads, and installed them? Have you checked to be sure that you have plugged the USB device directly into the main USB ports in the computer, or at least into a hub that is plugged into one of them? Have you checked to make sure that the USB port is set to accept USB 2.0 and not USB 3.0 (unless the new device says otherwise)?

Is it a dud? I don't know at this point.  Will it be fixed if there is a problem? That is partly up to you and others who report this problem.  The Devil is in the details and details are lacking from most people who have reported this thus far.

Have just had one delivered today and same problem. (Win8.1). The only paper instructions showed pictures of activating the batteries, plugin the transmitter and off we go. No mention of installing drivers before inserting transmitter. 

As noted earlier, the Desktop & Mouse Center do not appear to support this model. http://www.microsoft.com/hardware/en-us/help/windows-8/troubleshooting/mouse/supported-devices

I also have an Arc mouse which is the only device showing.

Is this likely to be fixed, or have I bought a dud?

You don't have a dud.  I think that the driver support was overlooked and updated drivers will eventually come if MS is monitoring these message boards.  My keyboard didn't come with a CD and the instructions didn't imply that you needed one.  I tried installing the software both before and after plugging in the keyboard.  I also tried it on two other computers with the same results.

Besides, if you look at the support page for the software, you'll note that it isn't listed.

Thanks Scott, I don't think so either. Getting used to it and liking it. My original aim was to see if I could switch round the left/right backspace as I don't touch-type. Clearly can't at moment, but maybe it will change in future.