Thanks for the hints, but .. it doesn't work. I tried this a lot. As I knew the key should be F2, I pressed F2 the most of the times, but to make sure I also tried F1, del and F10. None of them worked. It seems the BIOS option is no more displayed at all while the boot menu for the selection between the 2 OS is displayed mostly instantly. Can a CMOS erasure help in this matter? Or maybe is there any software which can allow the "flush" of the starting settings from whitin Windos? Thx!