new minecraft launcher freezes computer when i pick or make a world

when i start up new luancher for 1.6.1 it doesnt let me in a world i pick one or make one and it either shows downloading terrain or the main menu and i cant do anything

i thuaght it would start up the world normally

What actually happened was...:
it frooze my computer every time i started it up

Steps to Reproduce:
1. open up new launcher
2. login to account
3. pick a world or make one