u/Just_for-a-question

Hi, so my computer is connected to wifi and there is internet (im typing this from the same wifi network) yet i cant enter anything on my computer. I tried to fix it by resetting my wifi settings and stuff but it didn't help, my clock is correct so those aren't the problems. Also this might be because of something my friend did couple days ago, he opened dpn stettings(?) but since i can't enter anything i don't know how to fix it. Please help and thank you before hand.