There is an activation tag, that has no description associated and is mostly used for questions concerning windows-activation (which exist as tag and has an appropriate description). I saw one question though, that used it in the context of activating an hyperlink in a website. If a more general tag than windows-activation is needed, it should be named software-activation, or am I wrong?
I agree that questions tagged activation should be retagged appropriately as it is ambiguous and redundant. Questions about activating software other than Windows should get their own tag as you've suggested.
Most of the questions under activation are about Windows activation, so we should look at all of the questions under this tag and retag the questions about activating other software to software-activation. Afterwards, the tag activation can be merged into windows-activation. As part of this process, the tag wiki excerpt for windows-activation can be edited to direct users to tag other software activation questions software-activation, so that confusion can be avoided.
The hyperlink activation question has nothing to do with any of this, so I've removed the activation tag from the question.
All of the non-Windows activation questions under activation have been retagged accordingly, and I've proposed a tag wiki for software-activation. activation can now be merged into windows-activation.