hi , i had to factory reset my Laptop so i lost all of my wow installed game , i still have the disks but do in have to install each game now , separately?

No, Blizzard updated the patcher to download TBC and WotLK in the game client so there's no longer a need to install them. As long as you have your account registered with the expansions you will be able to access them when you start up the game.

You still need to install the orginal World of Warcraft game obviously, and you will need to reinstall Cataclysm as that isn't done automaticly through the games patcher.

You can install all the expansions from disc if you so wish, but do this before letting the game get to the launcher, otherwise you won't be able to install from the expansions discs once its started patching, without uninstalling the entire game again.