merging two different elements

Hello My problem is as follows,

I have elements installed on two different machines over a few month. now I have in each machine different developments, like tags and folders. I need to terminate one of the machines.

How can I merge the two differnt Contents????

Is there a way to avoid double entrys?

I am really a bit lost here, sinc I can not find any help in the adobe world (as I know it)

Thank you for any tips