Windows 8: Minecraft Horse Update won't work?

I have a windows 8, first of all. Everytime I update my minecraft to 1.7.2, it opens the new launcher. BUT when I close it and restart minecraft, it has the old launcher. Everytime I want to play, I have to re-update it to 1.7.2. I've tried uninstalling java and installing it back. I don't know what's wrong. 1.7.2 just doesn't stay.

Go ask at the minecraft website.

I have windows xp and its doing the same thing and I can't find out how to fix it