I have two systems on two primary partitions on one HDD with two separated BCDs, one for Vista one for 7 both with only one item, without prompt, the partition of currently not booted OS is hidden, so this works good. Over both BCD stays XOSL on last tiny partition, booted from USB Flash disc when insterted - it has highest priority.
But I have found a problem. When I hibernate one system and power on the laptop again, the XOSL don't appear, and hibernated system resumes automaticaly.
I think the OS must do something with BIOS, because the shortcut for entering BIOS menu is not visible, and BIOS is ignoring the bootable USB Flash, which has highest priority. After resume and reset, everything works as usual and XOSL appears again, so the change is only temporary.
Or can Windows temporary change MBR on USB so it don't call XOSL but BCD of hibernated OS ?
Is there any way to block Windows, telling BIOS to ignore USB/stop Windows editing USB and directly resume OS ?