Once you have marked the region, you need to transfer the text to the kill ring by either cutting or copying it.
Cutting text moves it from the current buffer into the kill ring, and deletes it from the current buffer, whereas copying just places a copy of the text in the kill ring.
Ctrl+Wto cut the text. In Microsoft Windows emulation the key is
Alt+Wto copy the text. In Microsoft Windows emulation the key is
Notice that these commands transfer the selected text to the LispWorks IDE clipboard as well as the kill ring. This is so that the selected text can be transferred into other tools, or even into other applications.
LispWorks IDE User Guide (Windows version) - 25 Nov 2011