... no no, you're a good helper.
i try a different grafics card today and maybe tomorrow change the mainboard.

thx so far, will post my results.

edit:
changed radeon 4870 to a geforce 6200 ... boots fine and installation fails at the end. (seems normal that there is a error message at the end of the installation process ... system boots )

so for my understanding: you have a usb boot stick to boot your OS with the dsdt file etc on it?