Hi Wiechie
That message usually means the disk is scratched/dirty or cracked. If the disk is cracked there is nothing to do as it means the data layer is ruined.
If the disk is dirty, simply wash it in lukewarm water and dry with a lint-free cloth.
If the disk is scratched you can try very gently polishing the scratch in tiny circles using toothpaste, then rinse in clean water and dry with a lint-free cloth, then try installing again. If it doesn't work, try polish a bit more. It's important to be very gentle while polishing as too much pressure or too much polishing will also ruing the disk.
If you don't want to try the polishing method yourself you could try ask your local library if they can help you. Some libraries has special polishing machines and if you offer them to pay they might help you.
If you are not able to make the disk work you can also buy the game on gog.com. It's legally DRM free
https://www.gog.com/game/emperor_rise_of_the_middle_kingdom
"Cats are the only animals that are both uber, pwns and 1337 at the same time." -King Euric
By reading this fine print your soul is now the exclusive property of HeavenGames.