I changed to Legacy and got the DOS message No Bootable Device - insert boot disc and press any key. changed it back to UEFI and it worked again for a a few days then same problem. I kept going through the switching between the two to get it working again and that worked 3 or 4 times. I even reset windows to a previous work point (thinking the problem was caused when I removed ACER programs on the laptop). Anyway bad news is, the switching doesn’t seem to get it going now. I feel pretty silly that I didn’t create a bootable USB when i managed to get it working again