Directly booting w/iReboot only works in one direction [EFI, Single disk, Win7+Win10]



This setup was working well until recently - not sure what made it stop but I haven't intentionally changed anything.
  • I have a single boot SSD, with Win7 and Win10 partitions
  • BIOS is in UEFI mode, Legacy boot disabled, Safe Boot disabled, FastBoot disabled.
  • Win10 has FastBoot disabled.
  • iReboot and EasyBCD 2.4 running in both OS, EasyBCD does not indicate any problems.
What happens:
Cold boot -> Boot menu appears, selecting either boot entry works as expected.
Running Win10 -> Select Win7 entry in iReboot -> Restarts directly to Win7 as expected.
Running Win10 -> Select Win10 entry in iReboot -> Restarts directly to Win10 as expected.
Running Win7 -> Select Win10 or Win7 entry in iReboot -> Restarts, but displays boot menu.

Any suggestions on how to fix this?
Answer to my own question:
1. Use EasyBCD's "Reset BCD configuration" function
2. Re-add BCD entries and save
3. Reboot, crash at POST w/No OS found errors
4. Boot to Win10 Install USB, use DISKPART to select disk and list volume letters, use BCDBOOT [driveletter]\windows
5. Boot to Windows, re-add BCD entries and save
@$zerbra thanks for posting back with your solution.

To shed some light on what may have been happening: it sounds like you had two different active boot partitions or one boot partition with two different boot profiles (MBR and EFI) and iReboot in Windows 7 was communicating with the a different bootloader than what your PC was actually loading with. iReboot just uses the default BCD store (e.g. bcdedit without bcdedit /store ....) and it seems that your Windows 7 installation was not picking up on the correct one (probably defaulting to MBR even though you were booting with EFI).

Your workaround probably nuked the MBR store and left only the EFI store, and once reconfigured, resulted in iReboot changes persisting to the boot stage across both installations.