Request for help to create dual boot

#1
Regards, gentlemen of EasyBCD.
I need help
I wanted to have a dual operating system. I had WIN10 installed and then on another partition I installed WIN7.
When I did this the WIN10 boot was deleted. Can I use the EasyBCD application to recover the WIN10 boot and have a dual boot?
 

Terry60

Knows where his towel is.
Staff member
#2
Can you post a screenshot of your Disk Management, showing the relevant partitions (annotated if it's not obvious which is which) and cut/paste the contents of EasyBCD "view settings" in detailed (debug) mode.
 
#3
Regards, gentlemen of EasyBCD.
Possibly, I did not know how to explain my problem.
The question is just to know, if the EasyBCD application recognizes WIN10 and can reinstall it in the boot sector together with WIN7?
Thanks for your attention
 

Terry60

Knows where his towel is.
Staff member
#4
That's why I asked for that information, to see what your current situation is and assess what you need to do to to get W10 access back.
 
#5
Friend Terry.
I thank you very much for your attention and for your concern to help me.
Initially, I wish to apologize to you for the way I wrote my initial application. I made a mistake in doing so and I go to your patience to understand me.
When I did the situation, this question was simulated. I did so because I believed that in this way I could simplify my exposition.
The reality is this:
I have on a computer that has a hard drive with two (2) NTFS partitions. In the "C" partition I already have WIN10 installed. The other partition is clean. WIN7 has not yet been installed. I expressed myself by simulating a future situation, because I am convinced that if I install WIN7 on the partition next to "C", the boot sector will be reinscribed and I will only be able to enter WIN 7. I will no longer be able to access WIN10. I understand that to have two S.O., the correct thing is to install WIN7 first and then WIN10. But in my case I do not have the original installation CDs of WIN10, because this S.O. I got it on offer from Microsoft. I want to install WIN7 but without losing WIN10. So my question was, if the EasyBCD application, when I install WIN7, can help me recover access to WIN10 so my computer has a dual boot system.
Thank you.

P.S. I do not speak English. All the text I elaborate in Spanish and then I use a translator to transcribe it.
 

Terry60

Knows where his towel is.
Staff member
#6
Omar,
I'll try to keep my reply simple so that Google translate doesn't mistake what I say.
You're correct in your thought that installing W7 after W10 will cause a problem, but it is easily fixed.
MS bootmgr for each version of Windows from Vista to W10 has code to recognize any older version of Windows, but cannot obviously know about versions which were created at a later date than itself.
When you install W7, if it replaces W10's version of bootmgr (larger) with its own (smaller) version, it will not accept the W10 version of winload.exe as genuine (invalid digital signature error)
If you make a copy of the W10 version of bootmgr somewhere safe before you install W7, you can then copy it back again after installing W7, to replace the W7 version.
Both versions of Windows will then automatically be bootable successfully.
If your PC is BIOS/MBR you will find the bootmgr module in the root of the partition flagged as "system" in Disk Management
If your PC is UEFI/GPT you will find it in the EFI System Partition.
It is a hidden system file, so you'll probably need folder options set like this to see it.
 
#7
Omar,
I'll try to keep my reply simple so that Google translate doesn't mistake what I say.
You're correct in your thought that installing W7 after W10 will cause a problem, but it is easily fixed.
MS bootmgr for each version of Windows from Vista to W10 has code to recognize any older version of Windows, but cannot obviously know about versions which were created at a later date than itself.
When you install W7, if it replaces W10's version of bootmgr (larger) with its own (smaller) version, it will not accept the W10 version of winload.exe as genuine (invalid digital signature error)
If you make a copy of the W10 version of bootmgr somewhere safe before you install W7, you can then copy it back again after installing W7, to replace the W7 version.
Both versions of Windows will then automatically be bootable successfully.
If your PC is BIOS/MBR you will find the bootmgr module in the root of the partition flagged as "system" in Disk Management
If your PC is UEFI/GPT you will find it in the EFI System Partition.
It is a hidden system file, so you'll probably need folder options set like this to see it.
 
#8
Friend Terry 60
Thank you very much for your prompt and careful response.
My PC is BIOS / MBR. It encourages me to consider the matter of easy solution. My understanding is this: The bootmgr starts winload.exe. To apply your recommendation I must First copy the bootmgr of W10 in safe place (Ejp: pendrive). After installing W7, I will overwrite the W7 bootmgr, with the W10 bootmgr, and then restart the PC, it will have the option to boot both Op Systems (Dual Boot)
Thanks again. Then I comment the results
Bye, Bye.
 
#9
Terry 60: Excellent work here and on other threads, your posts were very helpful for me. The program works very well, ( dual booter on separate SSD's ), I won't hesitate to recommend it. I struggled a bit trying to dual boot 7 and 10 without it, found your software invaluable. Thank you for your nice thread on the fast boot in 10. Had the BIOS not showing after shutting down in 10, ( booting straight to 10 ) although EasyBCD on both drives, and would boot perfect after 7 shutdown ( 7 set in 1st position on BIOS ).
Best regards and thanks again.