I have the Tbook 10, and I too unknowingly removed the dual-boot option from power-up. I have gone into the BIOS, and can’t for the life of me get that option back. The three options are Android, Windows, and the EFI shell, but the EFI shell (For me at least) just goes into a prompt – nothing happens.
I CAN switch between the two OS’s inside each other, but I was looking for Chris’s magical tri-delta thingy to re-enable dual boot from within windows…and I can’t find anything of the sort…
<sigh> – any thoughts?