Roy -- other Uru experts will help refresh my memory, but as I remember, you can play the whole game from the beginning with the expansion packs already applied if you want (Uru: Complete Chronicles, for instance, I believe installs everything -- the main game and both expansion packs -- at the same time).
If you wanted to, you could play Ages Beyond Myst and then install the expansion packs. But it isn't necessary to wait to install them.
I hope this makes sense!
Last edited by Becky; 07/27/11 04:46 PM.