How to reinstall Amnesia!

[AaronLS]

So I'm trying to re-install Amnesia after a long while...... And for some reason I can't remember how to install it. Every time I go and try to install it, the last part always asks what disk I want to save it to, now I bought the game..... I have Windows if that helps any.... But I just can't seem to get past which disk or how to save it somewhere, It just won't let me save to the desktop.
But I go and open it up to the Amnesia set-up wizard and follow everything and save the files to the same files again. I'll install it to the same folder, I'll make sure i get a desktop Icon and then it will say "Install", but it stops me and asks for a disk. What do I do from here? It will ask for the next disk, but I bought it online so i have no clue what to do. And then I'll have to quit it and it'll say "Rolling back changes" and I'll have to start again... Anyways enough ramblin'
Please help, this is getting stressful now and I just want to have a good scare y'know?