I got a new PC (without PS/2 Mouse and Keyboard Ports). The wireless keyboard and mouse (Logitech MX 700) are connected via an USB port. Legacy Support in BIOS is enabled. When the OS-Selector screen shows up in the boot process, I see a mouse pointer, which I can move in the vertical direction, but not in horizontal direction. I tried the options "Standard" and "USB or PS/2" - both with the same rsults. The same mouse works well, if I boot Acronis TrueImage from CD.