I want to download minecraft demo and it wont work so i updated my computer and it still wont work

Put the summary of the bug you're having here

*What I expected to happen was...:*it would let me play the demo
Describe what you thought should happen here

What actually happened was...: it said i had to update my cpu so i did but it still wont work
Describe what happened here

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