I get this error message before the game loads up. I already have the game installed on my computer.

"Emulator Detected. Please deactivate virtual Drive and emulation software"

I do not have an emulator on or running but I do have one installed, magic disk

what can i do to be able to play the game?

Welcome to the Forums!

Take a look at Installing and Re-Installing EoA, "1. Preventing Installation Problems - General Comments" in Myst V: Clean Boot Install/Re-install With Win XP.