For some reason since yesterday there's some site that either if I use chrome or safari I can't enter, getting notifications like "google chrome could not find x site" or "safari could not connect to the server". I know the site isn't down, so what's going on?

Try rebooting your net. 

I don't think that would work. My PC and phone don't share the same line and none of them load the site. May it be something related to the company we have the internet contract?

 

She site sometimes very randomly loads but stops working again:/ Also, if I open it in private mode a different messages comes up: "This webpage is not available"...

Edited May 17, 201411 yr by strike

Which site is it?

I don't think that would work. My PC and phone don't share the same line and none of them load the site. 

Doesn't make a difference. Number 1 rule when troubleshooting IT problems - turn it off and turn it on again.

 

Reboot all your network gear. Turn off your modem and routers and leave them off for at least ten seconds before turning them on again.

 

Also reboot your PC.

 

Have you tried pinging the website via the command prompt?

Nevermind, everything is back to normal.

Tom, the problems began yesterday, I had the wifi moden and pc turned off at night yet this morning it still didn't work. Perhaps it had something to do with the occasional problems the cable company has been having these days. Thank you guys for the help, anyway.