SQL server 2012 restore wizard freezes
@Pat I have been facing the same issue for a long time, but a few minutes ago found way around it.

First of all DO NOT try to restore by right-clicking on an empty database. What you need to do is right-click on Databases and from the menu select Restore Database. In that UI you can use the Files option and the UI won't freeze.

Note: By doing this SQL will create your DB and restore into it in one go.

Hope it helps.