press save in the mapper.

Yes I know. I want to know how one saves the keymaps or where are they stored so one may use the same remapping on another dosbox install on one of my other machines?

if you open the captures folder, then the keymapping file is one folder above that.

I can't find any caption folder. I checked in dosbox 0.74 options.bat and it's assigned there as captures=capture.
I looked in the program files\dos box directory and there was no capture subdirectory so I created one and then ran the keymapper again and saved it but there's still no data in the capture folder.
Where is the capture folder supposed to be? This may sound stupid but I did a search on the whole computer for anything with capture in it and it found nothing ( that was before I created the capture folder ion the dosbox program directory.) Maybe I put it in the wrong directroy.
Also when you said "one folder above that" I"m not sure what you were referring to. I guess if I had found the capture folder I may have understood.

if you got dosbox 0.74 from dosbox.com a LINK to the capture folder should be in your startmenu
"Start/WinLogo Menu"->"All Programs"->DOSBox-0.74->Extras

As you said there is a menu that has the EXTRAS but there is no CAPTURE thing at this time.
Here's the suboptions as they appear:
-Video
-Dosbox 0.74 (No options)
-Screenshots & Recordings
-Uninstall

-Screenshots & Recordings

Thanks - it's there.