Surface Pro 4: With Secure Boot enabled, can't dual boot Win - Microsoft Community

see thread title.  didn't notice until tried 16193, it's weird.

my sp4 dual boots between 15963 , latest insider build.  it's never been problem before, there's issue when try boot public build (the insider build on main partition).  secure boot enabled, trying boot public build kicks 0xc00000e9 error , says device needs repaired.  booting insider build never has slightest issue.  yet, disable secure boot, public build comes no problem.

this gets interesting. have usb stick iso public build on it, plugged in, thinking i'd boot , run recovery tools advised.  no luck--no matter did, wouldn't boot usb drive until (again) disabled secure boot.

since i'm not running on of non-insider machines dual boots else public build (one machine triple boots, between xp, 7, , 10), i'm hazarding guess insider build somehow responsible.  i've got no problem leaving secure boot disabled when want use public build, unusual enough problem figured i'd ask if else had run it, , if so, did solve it?

alright, l got solved.  secure boot disabled, booted public build , did in-place upgrade, misbehaving insider build.  once finished setting up, powered sp4 down, re-enabled secure boot, , once i'd renamed bootloader entries, everything's in order.

still weird problem though.

Windows Insider Program / Windows Insider Preview / Performance and maintenance / PC