Bob Browning's blog

So it seems that my Dell Optiplex 745 (a fairly recent model) comes equipped with a network card that does not support ‘TCP Window Scaling’ – whatever this is. The effect of this is that Outlook, Skype, and Windows live messenger all fail to work.

You have to type this at the prompt

netsh interface tcp set global autotuninglevel=disabled

which disables it until windows encounters a problem and decides to heal itself when the process starts over again.

Aaaaarrrrhhhh…!