Dual Booting 2 x Windows 10 OS Drives (Existing Installs)

Hello Xtownman Welcome to the Ten Forums!

When you say twin upgrades from 7 to 10 are you referring to having two separate editions of 7 such as 7 Home Premium and 7 Pro each upgraded to 10 Home and 10 Pro? each on separate drives? To add a boot entry for one of the two you can easily download a BCD editing program called EasyBCD which can add the boot for into the BCD store(boot loader configuration) of the 10 upgrade that happens to be on the drive set as the default Disk 0 usually but not always but which drive is set as default in the bios set up program.

Note for each and every download of the EasyBCD program or other free OS utilities seen at Neosmart you will have to re-enter the email address used the first time to register at the sight there. This allows support to contact you as well as you to contact them if you have any problems with the free for home use of their utility programs. Buy options are intended for corporate and other then home type applications.

If you elect to see the upgrades which could become buggy replaced by a clean install of one or the other that will automatically detect and add the boot entry in for you. You can also reset the default OS by opening up the msconfig tool by right clicking on the Start button and scrolling down the right click menu there to the "run" command line option and simply "msconfig" and press the enter/return button to bring that screen up where you click to open the Boot tab and click to highlight the other 10 to see it set as the default. The time out option for how long the boot options will remain in view default 30 seconds can be adjusted there as well as when using the EasyBCD options.

It is uneccessary to do all of the above.

1. Boot up Windows 10
2. Open Disk Management and take a note of the drive letter of the other Windows 10
3. Open Admin Command Prompt and type: bcdboot X:\Windows where X is the drive letter noted in step 2
4. Reboot, you should have a dual boot menu.

You can simply slap a boot entry in with a command but won't be able to set or change which will be the default or even back up and restore the mbr without a little help.

The EasyBCD program allows you to review as well as edit the boot entries including seeing them renamed which can quite useful for you there since you are running two not just one single 10 upgrade install. Instead of seeing "Windows 10" twice on the boot options screen you can easily see "Windows 10 Home or Pro 32bit or x86 if not 64bit or x64" applied according when going to rename one or both entries! To get a better idea on how that would turn refer to the guide on dual booting 7 or 8, 8.1 with 10. Windows 10 - Dual Boot with Windows 7 or Windows 8 - Windows 10 Forums

Night Hawk said:

You can simply slap a boot entry in with a command but won't be able to set or change which will be the default or even back up and restore the mbr without a little help.

The EasyBCD program allows you to review as well as edit the boot entries including seeing them renamed which can quite useful for you there since you are running two not just one single 10 upgrade install. Instead of seeing "Windows 10" twice on the boot options screen you can easily see "Windows 10 Home or Pro 32bit or x86 if not 64bit or x64" applied according when going to rename one or both entries! To get a better idea on how that would turn refer to the guide on dual booting 7 or 8, 8.1 with 10. Windows 10 - Dual Boot with Windows 7 or Windows 8 - Windows 10 Forums

What ever you said here, can be done without easybcd.

EasyBCD was designed to simplify things rather then to complicate them since many will automatically prefer a gui option. Plus you have to consider the possible want to change something later once the entry is added and not simply to removed but tweak things. And what about a possible triple boot coming up? This will be strictly Xtowman will need to decide for himself there however as all we can do is point out the options.

Sorry but I am not trying to complicate anything but just doing 3 steps below then you are done. No need to install anything.

1. bcdboot X:\Windows
2. bcdedit /set description "Menu description goes here"
3. To change boot order, run msconfig then set whatever you want to run first to default

Hey EasyBCD is simply an option. I found it reliable however since dual booting XP with Vista when that was first developed and have the latest on the 10/7 dual boot across drives seen on two separate desktops. Plus I have to set up another dual boot on another desktop where the owner has a reading disability to simplify things for that person's use.

For those who are "Tech Savay" on the other hand they will likely pay a visit to TechNet and be familiarized with the BCDEdit Command-Line Options covered there. That covers a potential list of errors as well as listing the various command references.