Well, Windows 8 has no Start Menu any more and the startup folder has disappeared also.
Where can I find that folder? Or is there a new way with Metro?
Solution:
It can be found here:
C:Users%USERNAME%AppDataRoamingMicrosoftWindowsStart MenuProgramsStartup
or easier to access with this command in the Run Win+R prompt:
shell:startup
Here are even more explanations of how accessing/viewing the startup folder.