I am surprised byyouranswer.
I'min the same case.
I have aHDMIadapter- VGA.
It works on HPandDELLlaptopbut not onmy ToshibasatalliteU920T.
On this hardware I just have aHDMI portand I usethisadapter to connectmy computeron video projectors cause it just hasVGA input.
WhenI plug thevideoprojetor,windowsdetectsa new monitorandthen deletesitrepeatedly.
any solution?