I don't know why my comouter wont accept the files. I see the mojang sign for minecraft start up, then the window closes and minecraft says i crashed.

Put the summary of the bug you're having here

What I expected to happen was...:
to play 13w19a after the file downloaded.

What actually happened was...:
the window closed itself and crashed.

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...
3. ...