I had an annoying problem with Macrium Reflect only displaying in low res 640x480 mode in winpe mode booting from a usb drive. Interestingly, it worked ok when booting from a hard drive partition.

I tried many fixes and got nowhere until I bought Home and could ask their support team.

It turns out my bios could not cope with win5(crashed) or winpe10(Low res only). Once I used winpe4 it worked - high res!

Not only that, I could now see my second hard drive!