Start by uninstalling/reinstalling the game itself.
- Go to Programs and Features and uninstall Assassins Creed.
- Once done make sure to delete all the left traces of the game.
- Go to Computer>C>Program Files> and look for any folder related to that game and delete it.
- Or better yet uninstall the game using a 3rd party software to completely delete everything . (Revo Uninstaller)
- Once done reboot your laptop then re-install that game and see if it will work or not.
- Just to be sure do also a clean install of your graphics card driver.
- Please refer to this link on how to do the clean install of your graphics card: http/www.tomshardware.com/faq/id-2767677/clean-graphics-driver-install-windows.html