Thanks, I'd already seen that solution... but my tablet Surface has only 1 USB 2.0 port...
"Ok. I have a fix after being in contact with acer support Norway.Started with deactivating signed drivers during advanced startup.The the solution is to plug the main usb connector into a 2.0usb instead of a 3.0jack. The slave i plugged in the 3.0usb instead.If the screen resolution must be set at 1280x768 or less.This popped the driver install window and everything worked"