hi,

i got decent/fast internet .. every game i play runs smooth.
but when i start diablo 2 through the launcher .. everything stops, all connections drop, internet doesn't work anymore, and diablo 2 server crashes to... can't stay in a game for longer then 10-15 seconds.

as soon as i close diablo 2, everything else starts working again.

if you turn your firewall off temporarily does it still happen

Mabey d2r is beefer than you thought.

Are you able to bypass the launcher? Have you tried a fresh install to a different drive?