This works well with PC number 2, which is running WinXP. However on PC number 1 which runs Win7, it causes some issues. If I try to use it as 2 PC's to 1 monitor only, the display is a bit odd - kind of dull (unless I plug the usb lead in, PC number 2 is fine without the usb connection)! If I plug in the usb connection, and connect a usb keyboard to the KVM Switch Box, I get problems on my Number 1 PC's usb ports - they 'do not recognise' devices plugged in. The Number 2 PC does not have any real problem, but every time I switch back to it it has to 'reinstall' the Switch Box, which is a minor irritant. I hope this is helpful.