Thanks OldSteve
This tip did the trick :)!
I am effectly using an old PC with Windows XP , but it has worked fine for
a long time and with scores f applications . But now I downloaded the IDE 1.6.11
and then the problems started ... This version though when installing checks the
prsence of older IDE:s and then erases it/them ... so , fortunately I had another
PC with 1.6.8 installed ... copied that LD.exe and ,...Yuipee!!!
But I must admit I am surprised the Arduino software people have let through a
bug like that ...