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In other words, it fails to recognize Sculpt Comfort Keyboard when it's alone, and recognizes it just in pair with mouse.
The problem now is that I don't know what to do with single keyboard now ]:->
Microsoft sells the Sculpt Comfort Desktop, but they are not listed here either: http://www.microsoft.com/hardware/en-us/help/windows-8/troubleshooting/mouse/supported-devices
Only the Sculpt Comfort MOUSE is there, the Keyboard and Desktop are not. Do you agree?
That can be called an ackward mistake made by Microsoft for sure.
Microsoft has updated hardware components. They are not under obligation to support older hardware constructs when newer is available or when they discontinue an older version or other hardware series. They aim for backward compatibility but this is not always possible.
For those with older hardware (yes, even the retail and online stores still sometimes sell outdates hardware) they are recommending uninstalling mouse and keyboard center and using the IntelliPoint Software instead.