Selective blocking by my PC

The crux of the problem is that my Internet seems to be blocked to certain sites/programs. I have no idea why or how and cannot figure out how they were selected.

For example: uTorrent will work and dl torrents, Steam can connect to the server, however League of Legends will not let me login.

Chrome, Firefox and IE (shudder), will allow me to visit my most familiar/regular sites, but ones such as eBay, First Row Sports, Fantasy Premier League etc. won't load and I get " Oops! Google Chrome could not connect to fantasy.premierleague.com

Try reloading: fantasy.­premierleague.­com".

I've added rules on the incoming and outgoing sections of my firewall, i've added the sites to trusted sites in internet options, i've now uninstalled avast to see if that was impacting on it and i'm still getting nowhere.

I do have Advanced System Care on. That's my next target.

It literally went from working today, I then disconnected my tower, vaccuumed and put it back together and a few hours later it's not working. I played a game of League of Legends this afternoon after vaccuuming and it was fine.

If you have any idea, please let me know.