Black box error - Please help me

[Lyvlet]

Well i've been able to install it- that's how far i came. aswel. where do i find 'verify integrity of game cache'
as i absolutely have no idea where to look for it

Yes, it is supposed to create a folder named Amnesia under the Documents folder.
Are you able to see Launcher when you open it through Steam? Also, try to do a 'verify integrity of game cache' in Steam for Amnesia.