Using 2 accounts

hi why in the hell cant i use 2 account i have purchased 2 copys got 2 battle net accs and i was able to play at same time with my gf off same pc so wtf is the issue of not being able to play 2 accounts all a sudden like if yall gonna scam ppl out of money like that refund my 2 pc copies already bought 2 on xbox and now this bs ???

You need 2 Computers

I don’t know if it still works:

nah u didnt i was playin 2 games off my pc bro till today with there stupid new launcher patch