Changing PC's with Auto Enrolment enabled

Hi,

I have user based auto enrolment enabled via GPO.

We are rolling out new laptops and the user cert inst being delivered to the user's cert store on the new laptop. 

Is this by design and I will need to reissue certs to the users (via request new cert in mmc on the new laptop) or have I missed something with the setup and the certs are meant to be on the new laptop?

Cheers

Chris