[SOLVED] Booting from Windows 7 drive after installing Windows 10 on different drive

[NBK2014]

Hi, I installed Windows 10 on an m.2 ssd. It automatically decided to set that as my main boot drive and in my bios, and windows boot options, the other drive where windows 7 was installed isn't listed as a boot option. I didn't remove the other drive before installing windows 10 unfortunately. I'm starting to notice a lot of minor things on windows 10 that i don't like and i'd like to be able to boot from my other drive with windows 7 on it, the issue is that i can't find it as a boot option at all. i've seen videos of people dual booting win 10 and win 7 but it seems they're creating new partitions and doing a fresh install. is there any way to have both in boot options and choose which drive i want to use?

 

[wpgwpg]

Get EasyBCD. It will let you set dual boot options to your liking. I've been using it for years. It's available for download on the Neosmart web site (neosmart.net). I've been using it for years.

 

[NBK2014]

Get EasyBCD. It will let you set dual boot options to your liking. I've been using it for years. It's available for download on the Neosmart web site (neosmart.net). I've been using it for years.

thanks for the software, seemingly it's what i want. upon booting the software it said i had an EFI system so some features required a workaround. i added a new entry for the other drive, and it seemed to start to boot there just fine, except that it was taking way too long, longer than what i'm used to on that ssd/ after waiting i restarted and tried again, it gave more options like safe mode, boot with network, etc, but i couldn't use the keyboard to select any, it was unresponsive. it tried to boot anyway after 30 sec but still didn't manage to. i also tried BCD re-create/repair boot files and changed the boot drive to the other ssd, still didnt boot up as normal? is the other drive fudged or have i not used easybcd correctly?

https://imgur.com/gRP51en

View: https://i.imgur.com/gRP51en.png

the 256gb E drive is the ssdd im trying to boot windows 7 on, the other one has windows 10.

 

[wpgwpg]

I've never run into anything like you describe. It sounds like something with Windows 7 has gotten corrupted, but I couldn't say what.

 

[ohio_buckeye]

Honestly, best just to stick with 10. Windows 7 exits support next week. Best to just stick with 10. Once you get used to it it's really a decent system.

 

[onespeedbiker]

It's likely windows 10 may have loaded part of it's OS on the Windows 7 drive. Boot up win10 and post a photo of the Disk Manager. You can also remove the Win 7 drive and see if Windows 10 will boot

 

[USAFRet]

Hi, I installed Windows 10 on an m.2 ssd. It automatically decided to set that as my main boot drive and in my bios, and windows boot options, the other drive where windows 7 was installed isn't listed as a boot option. I didn't remove the other drive before installing windows 10 unfortunately. I'm starting to notice a lot of minor things on windows 10 that i don't like and i'd like to be able to boot from my other drive with windows 7 on it, the issue is that i can't find it as a boot option at all. i've seen videos of people dual booting win 10 and win 7 but it seems they're creating new partitions and doing a fresh install. is there any way to have both in boot options and choose which drive i want to use?

You had both drives connected when you did a new install of Win 10 on a different drive?

Test....
Power OFF
Disconnect the Win 7 drive
Power UP

Does it boot correctly?
I'm thinking No.

 

[NBK2014]

You had both drives connected when you did a new install of Win 10 on a different drive?

Test....
Power OFF
Disconnect the Win 7 drive
Power UP

Does it boot correctly?
I'm thinking No.

Yes i had both drives installed when installing win 10
It booted up fine with the Win 7 drive's sata cable disconnected. here's a picture of disk manager with the E drive gone:

https://imgur.com/oxYbG7h

View: https://i.imgur.com/oxYbG7h.png


i will boot up with the drive connected and include a picture of diskmanager with the E drive next

 

[NBK2014]

It's likely windows 10 may have loaded part of it's OS on the Windows 7 drive. Boot up win10 and post a photo of the Disk Manager. You can also remove the Win 7 drive and see if Windows 10 will boot

as in the above post, i tried booting with the drive gone, and it booted win 10 fine.
here's the picture of disk manager (the win 7 drive is E):

https://imgur.com/UQ5XZpO

View: https://i.imgur.com/UQ5XZpO.png

 

[USAFRet]

i will boot up with the drive connected and include a picture of diskmanager with the E drive next

How many physical drives are involved here? Two or three?

We need to sort of disregard drive letters. They change.

 

[NBK2014]

How many physical drives are involved here? Two or three?

We need to sort of disregard drive letters. They change.

1TB hard drive (just files), 256gb win 7 ssd, 1tb m.2 ssd win 10, 7.2gb usb with the win 10 bootable install

 

[USAFRet]

1TB hard drive (just files), 256gb win 7 ssd, 1tb m.2 ssd win 10, 7.2gb usb with the win 10 bootable install

OK.
I was assuming 2 drives, not 3.

Power OFF
Disconnect ALL drives except for the one that contains Win 10. Including the 8GB USB.
ALL storage devices.
Power UP

Does it boot correctly?

 

[NBK2014]

OK.
I was assuming 2 drives, not 3.

Power OFF
Disconnect ALL drives except for the one that contains Win 10. Including the 8GB USB.
ALL storage devices.
Power UP

Does it boot correctly?

Disconnected the Win 10 drive, tried booting with the win 7 (without the usb drive plugged in), it gave an error with a win 10 looking screen, 'your pc/device needs to be repaired, required file is missing: \windows\system32\winload.efi
error code 0xc000000e. so it seems it has overwritten the bootmanager on the other drive. my mistake was keeping the other drive plugged in when installing win 10, didnt know it would do this.

interestingly enough i tried booting it again, and it gave a different win 10 looking screen, with 'the boot configuration data file doesn't contain valid information for an operating system. this one might be to do with the easybcd software i tried using.

it gives options for recovery environment, which does not seem to start and just restarts the pc, giving the same screen, or for uefi firmware settings (goes into bios)

i will try booting win 10 with all other drives disconnected but i think it will boot up fine as ive already managed to boot it up without the win 7 drive, the other hd has no boot files, just files, and i doubt the usb makes a difference, but i will try it later again anyway.

is there any way to get back the win 7 boot manager on the win 7 drive? i will try to use a recovery disk on it later

 

[SkyNetRising]

is there any way to get back the win 7 boot manager on the win 7 drive? i will try to use a recovery disk on it later

Connect win7 drive, boot into windows 10 and show screenshot from Disk Management.

Could be - windows 7 is installed in legacy mode. Since windows 10 is installed in UEFI mode and BIOS is configured to boot into UEFI, windows 7 will not be available for booting.

 

[NBK2014]

Connect win7 drive, boot into windows 10 and show screenshot from Disk Management.

Could be - windows 7 is installed in legacy mode. Since windows 10 is installed in UEFI mode and BIOS is configured to boot into UEFI, windows 7 will not be available for booting.

I set Settings\Advanced\Windows OS Configuration\Windows 10 WHQL Support (Windows 8/8.1 Feature) = [Disabled]
then enabled UEFI + LEGACY boot in bios
EasyBCD already set two boot options for the old drive and win 10 drive, thanks, @wpgwpg
i selected the win 7 drive, it booted up fine, then restarted and booted up in win 10 through the boot menu, worked fine also, looks like i can boot from both drives with the default boot manager being on windows 10. i would pick both SkyNetRising and wpgwpg for best answer, but i can only pick one, so i will choose skynet's as it ultimately solves my problem by enabling uefi + legacy boot in the bios.

much appreciated to all