Dual boot Windows 10 & Windows 7 using 2 HD's

Install 10 then install 7 easy

Windows 10 uses a similarly structured boot management system to that in Windows 7, so an installation of either as a second system on another drive or partition will not affect the first. Disconnecting one drive to install the other is not necessary, and will mean that you will have to use your bios function to decide which system to boot rather than a convenient menu. I am not a great fan of the graphical boot menu, I would prefer the legacy text-based one like in Windows 7. With a utility like EasyBCD, you can do this after installation.

Depends what setup you want. If you disconnect the W10 disk, you will get an independent W7 installation to which you switch with the BIOS boot priority (I prefer that setup).

If you leave the W10 disk connected, then you will get a double boot with the W7 bootmgr ending up in the W10 bootmgr record. Both setups have their pros and cons.

I use 1 disk but I divide them to two
I can Dual boot fine
Windows 7 thinks it is last version so Windows 7 will delete 10
Windows 10 won't delete Windows 7 ;D
I'm not sure of if you install 7 then 10 7 will be removed
I remember it does
You're good to go Just install on the second hdd
no need disconnect

CountMike said:

Safest way to dual BOOT on two disks.
Disconnect one you don't want that OS on because you may end up with BOOT spread over both of them and if you remove one or BOOT from wrong one you can end up with no OS at all.
After installing that OS, you can use: EasyBCD - NeoSmart Technologies on first or even both disks to give you BOOT menu to chose OS you want to BOOT to.
That process never failed me even with various OSs, like Windows of all kinds plus Linux distros.

Completely 100% agree. You don't even have to install EasyBCD.

bcdboot d:\windows /d /addlast

run from an elevated command prompt will add the second Windows OS to the boot menu after both hard drives are reconnected. Path in red being to the second OS Windows folder.

Then you can run msconfig and the boot tab will let you set your desired default OS and timeout for choosing.

CountMike said:

Safest way to dual BOOT on two disks.
Disconnect one you don't want that OS on because you may end up with BOOT spread over both of them and if you remove one or BOOT from wrong one you can end up with no OS at all.
After installing that OS, you can use: EasyBCD - NeoSmart Technologies on first or even both disks to give you BOOT menu to chose OS you want to BOOT to.
That process never failed me even with various OSs, like Windows of all kinds plus Linux distros.

I realize this is an older thread, but I would like more info on this. I've been running Windows (7, then 8, and now 10) dual boot on two disks for quite some time with no problems until one of the drives started to fail (SMART EVENT and failed test) and I started having boot issues. When I removed the failing drive, I couldn't boot the remaining drive/OS, and had a nightmare repairing it because I couldn't boot the install DVD (finally got it to boot using a portable USB DVD drive!).

My original reason for two drive dual boot was so that when either drive failed, I could easily restore to a new drive from backups on the other drive, but unless I can set it up so that either drive/OS can boot if the other fails or is missing, it's not worth it.

I've replaced the failed drive, but have not yet put an OS on it. Any suggestions will be appreciated!

MacWin said:

I realize this is an older thread, but I would like more info on this. I've been running Windows (7, then 8, and now 10) dual boot on two disks for quite some time with no problems until one of the drives started to fail (SMART EVENT and failed test) and I started having boot issues. When I removed the failing drive, I couldn't boot the remaining drive/OS, and had a nightmare repairing it because I couldn't boot the install DVD (finally got it to boot using a portable USB DVD drive!).

My original reason for two drive dual boot was so that when either drive failed, I could easily restore to a new drive from backups on the other drive, but unless I can set it up so that either drive/OS can boot if the other fails or is missing, it's not worth it.

I've replaced the failed drive, but have not yet put an OS on it. Any suggestions will be appreciated!

Disconnect all other hard drives/SSDs except for the drive you want to be able to boot independently. After Windows is installed on the drive you want to be able to boot independently, then you can reconnect other HDDs/SSDs with operating systems on them. Decide which drive you want to be your normal boot drive and make that the priority in UEFI. Then use the bcdboot command to add the secondary operating systems to the boot menu. Since you installed the operating system on the secondary hard drive with only it connect, the secondary hard drive will still retain the boot files on it, they just will not be used until you tell UEFI to boot from it.

Doing it this way you can have 1 HDD with Windows 10 RTM on it, 1 HDD with Windows 10 Insider, 1 HDD with Windows 7. All three hard drives can have the boot files on them and using UEFI boot menu can pick which HDD you want to boot from. Using the bcdboot command you can add the other two operating systems to the boot menu of 1 HDD and not have to continuously switch which hard drive the UEFI boots.

You can do the same thing without disconnecting the other HDDs but you have to be very careful how your UEFI boot order is set up and how the blank hard drive you are installing to is set up so you don't end up actually putting the boot files on a different HDD and I don't really recommend that unless you really know what you are doing and how to fix it if it goes wrong.