My results,

- all USB options are enabled in BIOS
- used 2 USB Keyboards, one in front and one in back
- booting from CD => choosin "Run software installer" => loading => Licens Agreement keyboards still out of function
- preparing USB stick for booting, run "bootinst" (works fine), booting from USB (Corsair Flash Voyager 8GB) in the back of system => blackscreen

Tomorrow ill try on