Cannot boot from

#1
I have both Wins7 and Wins10 on the same computer, separate drives. I installed easyBCD on the Wins7 drive with the drive of wins10 disconnected. After setting the necessary info in easyBCD, connected the wins10 drive and rebooted. Everything was great. Then one day something went wrong and it won't boot. It says BOOTMGR is missing so I have restart use F8 to selected the boot drive. When I try to boot into wins10 it says there is a problem with a file and signature cannot be recognized. Any thoughts of what to do other than do a cold install of wins10. If I have to do that, will everything work since wins7 already contains easyBCD. I read one article on the Internet that said to install easyBCD on both drives. Thanks
 

Terry60

Knows where his towel is.
Staff member
#3
You cannot boot W10 with W7's bootmgr (or any newer Windows from an older version's boot manager)
You need to make W10 your primary system and add an entry for W7 into its BCD.
You can't do it the other way round; the result is always "Invalid dig sig". (The older bootmgr is not aware of the W10 winload.exe digital signature and treats it as pirated software. W10's bootmgr will be completely backward compatible with all the dig sigs of every previous Windows version)
 
#4
Terry 60: I am not an expert but that's not always true. I also dual-boot win7 and win10. Win7 is my factory installation on drive C where EasyBCD is installed. Then I installed win10 on a second driver and I believe it uses win7 boot manager. This is because when I boot windows 7, win7 is on drive C and windows 10 is on drive F but when I boot windows 10, windows 10 is reported to be on drive C and windows 7 on drive F. I use dual booting for 2+ months with absolutely no problem. The system itself recognizes what is C and what is F each time...I don't know how it came out, but my OS will always be C drive whether I boot win 7 or win 10. So I believe my old boot manager handles both OS.
 

Terry60

Knows where his towel is.
Staff member
#5
If you installed W10 after W7, W10 will have detected W7 and replaced its boot manager in situ with the newer version.
You might think it's W7 booting W10, but it's actually W10 booting both, but using the boot space previously occupied by W7.