Updating via Mac App store

[TomJeanes]

Hi all,
Is it possible to update to Yosemite via the Mac App store, or do I have to reinstall from scratch?
Thanks,
Tom.

 

[Robbish]

You can't upgrade to OS X Yosemite via the App Store but you can upgrade over your existing installation.

All you need to do is download Yosemite from the App Store in the usual way and then create your OSX Flash drive be it Chimera or Clover however when you reach the OSX installer via flash drive, just target your existing OSX installation/boot drive and execute the upgrade install to that.

The install will upgrade OSX keeping your previous OSX Apps, Settings and Data in tact but on Reboot, you will likely have to reinstall onboard network, onboard audio and trim if you use them.

BTW, you can perform OSX version (incremental) updates via the App Store no problem.