Minecraft crashing on startup and upon joining a world

Every time I open Minecraft, it will stop responding at one of two points:

1. During the 'Mojang' loading screen on its start up.
2. Trying to join a world, single and multiplayer.

I have tried multiple solutions including:

1. Reinstalling Java
2. Reinstalling Minecraft
3. Using the 'Repair' function on the installer
4. Installing Optifine
5. Installing the latest Visual/Audio/Etc. drivers
6. Changing the Java it uses on launch (javaw to java)
7. Restarting computer several times between each of these

And none have worked, or improved this issue whatsoever. I hope someone can help with this issue, but even if you can't, thank you for you time.