That would take a ridiculous amount of time.
Looking for some way faster
No he wants functionality in a picture viewer would be my guess.
Read your post and it came to me....just uninstall all of the useless (on a desktop or laptop) Metro apps.Yea, I'm sure of it. I wouldn't mind it on a tablet (the old argument returns!), but these are not desktop applications. I've gone through and replaced the Metro apps with desktop apps on most of the default programs (PDF reader, pictures, music, mail...).
Yes but on the other hand most of them aren't very useful. Most are not much more use than the annoying Desktop Gadgets of Vista.
I don't disagree that the Metro crap apps are useless but why not just run an installer for a view that xnview and then open the program and say associate with picture files. Much easier then writing a powershell script for the nth amount of picture file types.
Microsoft never encourages people to go backwards. Embrace Metro, make sweet love to it. Why would you go back to the way the things were before? Are you afraid of change? Are you a little terrified old person afraid of new and shiny thing?