Finally got the game working and after 2 days it no longer works

[OreGano]

I purchased the game, made it compatible with windows 10 and everything, then played it. It ran smooth and it was great fun.

However, today, when I open Fallout 3, it says that it may not work on my version of windows 10, then restarts the game continuously until you stop it. It also asks if you would like this game to make changes to your pc. Someone help pls I wanna play fallout 3.