When I try to play the demo I keep getting a website restore error

Please add a screenshot.

I cant it wont let me enter Minecraft.net anymore. All that shows up is a blank screen

What browser are you using? I think possibly your Java is the problem or the website itself is down.

The fact that minecraft.net shows a blank screen indicates a browser/computer issue. Resolving because Minecraft isn't at fault.

If you can provide more information, I would be happy to reopen this issue.