All right just a global view on what happend:
while installing:
VIsual C++ 6,0 Redistiribution Pack:
the required engine could not be found
missing IE 5.01 (it stoped install)
error:
String ERROR_DXINSTALL was not found in string table
installed IE 6 SP1 without problem
try repairing install
An error (-5006 : 0x8000ffff) has occured while running the setup
.NET 2,0 installed
nwn2 will show "start" screen, not further (do hear the music of menu/start screen)
installer will keep error (-5006 : 0x8000ffff)