Install on second computer

I have a standalone license thru a subscription service at work. I want to also install on my laptop. I have logged in and gone to the download page, downloaded the software and attempted to install it. The problem is that it is asking me for my serial number. We currently receive no new CD's with the software as we do everything online so I do not know how to get the serial number to install on the second computer. How should I handle this?  Thanks.

SolidworksAdministration