Can not connect everytime i want to play

When i try to connect, it text me just connecting and nothing else. Sometimes it text you have to convert your acc from battle.net. (i use my login no email) I try wotlk realm and panda realm. Sometimes it work great. But sometimes i stuck in connecting. Try everithing. My friend next to me conect to same internet then me. He connect without problem but i cant. I buy new Lenovo y50 wind 8.1 and problem with conect to warmane begin. Every other servers run perfect.

Delede WTF (dont work)
Delete Cache (dont work)
use SET in confing (dont work)
I read forum but didnt find aswer.

Pleas help me guyz i love warmane but sometimes i cant play all day....