The Launcher will only allow you to download an engine version with the latest hotfix. It’s likely that you downloaded 4.7.2 on your laptop when that was the latest version available. Now 4.7.6 is the latest most stable version of 4.7.
If you definitely need to have 4.7.2, you can still get it by building it directly from source that is available from GitHub. However, I would suggest updating the engine on your laptop to 4.7.6 if that’s feasible.