Can you expand a commercial license on 2 differenent operating systems?

Is It possible to expand a sketch up pro license wich was bought for a mac os system up to a second device wich runs Windows ?

a license of the recent SUP version 2015 is a cross-platform license, i.e. can be used on both platforms… of course alternating and by the licensee only. If you have the need for using parallel on both platforms a second license is required.

License Types : Single User:

A Single-user license is assigned to one person and can only be used by
the registered user. That individual can install the license on two
computers that they use. This is typically a work computer/Desktop and a
laptop. Click here for SketchUp Pro Pricing, including quantity discounts.