Freezing at loading screen, *Solution!!*

[niguz]

Just ALT-F4 then start wow again and it will work.

[Servus_]

Just thought i'd chime in and say the reason this works is because each time the wow client needs to load a zone it has to check with the server if it can do that (you might remember an instance server going down and the load bar never fills past 0%). The problem is that if theres some conflict with your internet connection and their registration of your logging in from that internet connection, it may never tell your client to load or stop loading and it will hang.

TL;DR: before it loads it needs to check with the server, server no reply? no load.