Pages don't load unless going through proxy!

Hello guys , so here is my problem some pages that are up and running don't load on my pc. I have tried every browser so far , have changed DNS from deaful to Google Dns i have clear everything in my browser and the problem still persists. The strange thing is that these pages (all of them) load fine through proxy! also some of these pages have no www in forn of them (exammple: bitgamer.ch or k3yforums.com) I have searched Google but found nothing, so i am up to you. Thank you so much!

Do you get faced with a certification error when browsing to web pages, like the picture attached.

no nothing similar to this. The thing i get on Mozilla is this: it is in Greek language it means problem loading the page!