How do I keep my certificate on 2 Laptop.

Hi
Currently I have 2 Laptops and I want to be able to export my game to both Laptops, but when I upload an apk game to google from one laptop or another it tells me that the certificate is different and I would like to know how I can keep the same certificate on the 2 laptops

Thank you

http://www.stencyl.com/help/view/google-play/
I reckon you can simply export/save your original certificate somewhere, send it to your second computer and select that.