I have a problem with only one website that won't refresh no matter what I do. I've tried deleting cache, cookies etc.
I guess something is wrong with my computer because everyone else sees the updated version of that website.
Have you tried restarting your router? This can sometimes fix the issue. Also note that some websites (like youtube) don't update their layout for all users at the same time. Probably to find bugs etc they release their design to a small number of people first and then release the update to the rest of the world. Also there are a few more possible scenario:
1) You have a firewall
2) You have a virus
3) Your ISP blocks the website update for one reason or another.
Assuming that this is a website that you've built - if it's CSS-related, try adding a parameter to the CSS links to force the browser to fetch new versions of the CSS files, e.g.