I’m so bad at computers so If someone can explain in the most simple way I would appreciate it. 
I use SktechUp 7 in my 8 year old iMac, but my iMac is getting slow so I wonder if I can use it on my Macbook Air instead. You can’t put in a CD in it you know so I wonder how I do that then. Maybe I should upgrade SketchUp as well?
You can download the SketchUp installer from the SketchUp website so you don’t need a CD.
Probably SketchUp 7 won’t work properly in a newer version of the Mac operating system, so you might need to upgrade.
Anssi
Ok. But when I tried to do so it says:
It looks like you’re license has been deactivated and is not eligible for upgrade. If you feel like this is a mistake, please contact us.
Should I just get a new license then?
I tried to download a older version (7) but then it says that my license is for an older version. ?