@Anonymous:
There are two other threads about this exact thing from within the last week. I realize this response is based on your search, but there are newer threads that answered this question, as this thread is from last december..
Anyways, here is what I wrote in response to the other two threads:
@epic41 wrote:
"If you turn off 'Capture Design History' in the lower right-hand corner of the screen you can copy and paste entire sketches..
..otherwise, with only the sketch you want to copy visible, you need to click-drag over to select the objects you want copied and then right-click and select copy. Then, hide the old sketch, activate the proper component, select the proper plane, start a new sketch, and paste. You should see all the objects populate your new sketch.
I haven't had to do that process for a while so someone please correct me if I am inaccurate.
There are some (special) features that are only available when design history is off, but then you don't have a design history.."
That is from here and here, two recent threads on copy/paste..