Multiple instances of Windows 10 on a single computer

So, I use my computer in 3 ways: Work, School, Personal. Lets call them ‘lives’. I want to do separate windows installations on different hard drive partitions but I only need to run one at a time. This started from the issue that I have three separate Microsoft 365 subscriptions, one for each. Which encorporate different services. I also have things like powerBI twice, once for work and one for school. It is becoming a major pain to deal with, having to make sure I’m linked to the right office/outlook at any one time. I’ve ended up with school files on the work cloud, etc.
Also for work I am using WSL, for the development enviroment, and I feel that unneeded backround services are running when I don’t need them and are impacting performance.
I thought I could solve this by using different user accounts, however from my research, you get one install of office per PC. So you cannot load up multiple versions. Even if you use different accounts. Finally service accounts seem to run at a per machine level, not a per user level.
Again according to research, not only can you install two different versions of windows and select which to use at boot time (example But this can be done with two identical versions of windows 10. as long as they are on separate drives, or even just partitions of the same drive. Is anyone doing this currently? Have suggestions on pitfalls or issues?

Thank you for your time.

I would suggest you use separate disks for the task but theres no real disadvantage to this kind of setup aside from maybe having to reboot a lot.

I can handle rebooting. Now just need to pay the windows tax, or find an old 7 license kicking around. Is there a compelling reason to get retail over OEM for this?

Well if it’s a laptop it probably has a digital license and you can just install a windows you download from MS.

I run multiple copies of Windows 10 on a single computer without problems. But they are on separate disks, and i would encourage you to do the same. I run multiple versions of Linux on the same disk without issues. But I have been badly burned, more than once, having any other OS on the same disk as Windows. Data partitions don’t seem to have issues (and are easier to back up).

As I recall, when it became necessary to restore from backup or repair Windows, the Windows tools strongly assumed a single OS and happily overwrote other data on the disk, wiping out other OSes. In addition, the Window “fast boot” mode leaves a “Windows drive” (disk or partition) in a special state that confuses another copy of Windows.

(Fast Boot may cause problems if two copies of Windows access the same “Windows drive”, even if the two copies are on different disks.)

Good luck.

Thanks for the input, unfortunate about the separate drive thing, as I only have 2 NVME drives. When running two versions on the same drive did you happen to have another on a third? I’m wondering if I just put the two most ‘loseable’ instances on the same drive the problems you described will not risk the primary if it is on its own drive.

Do you think yanking the NVME on which the “precious” partition resides would protect it, and not screw up the reload?

I appreciate your input

Okay, let’s see. I had terrible experience with Windows native backup-restore software; restore tended to wipe out much or all of the disk on which Windows was installed, usually leaving Windows itself unusable. These days I use third-party backup software, with much better results.

I never saw Windows mess with data on other drives when attempting to restore, but removing other drives might be a good precaution if doing restore or other operations that aren’t part of the usual workflow. I do remove other drives when installing Windows, because I have seen it make changes on other drives then. I think this may be better these days, but I lost all confidence and haven’t regained it.

If you only have one NVME in the system whenever you are installing software, it should mean you can yank one or the other without causing problems. I’m assuming UEFI firmware, and some UEFIs used to be unreliable about recognizing bootable software when a disk was put back in the system. My experience with this has been good in the last few years, but I also count on being able to fall back on Linux efibootmgr to fix any problems.

It sounds like I am discouraging you from experimenting, and I don’t want to do that. My bottom line would be to be sure you maintain good backups, and don’t do risky work when you can’t afford any downtime. I never lost any data of value, but I did have to spend hours re-installing OSes. Then again, I am pretty active at making changes to my configuration and installing different OSes just to explore, and that indirectly led to many of the issues I faced.

Maybe others would care to weigh in with their own experiences? Anyone out there?

Why not using more Useraccounts? Each User can have its own Desktop and Set of installed Programms.
Just use a big Drive for Data and begin it with different folders for any User.

Microsoft Office is licenced in two different ways:

  • Per user. This is the way Microsoft 365 / Office 365 works. It needs a Microsoft account login within the Office programs.
  • Per device or computer. Office 2019 works on this basis and it’s the way all past Microsoft Office worked for many years. Anyone using a computer can use the installed Microsoft Office

Just use individual MS Accounts

That is what I was originally going to try, but I have three different sets of Microsoft 365, with different programs and features included.
While some programs can be installed separately on a per user basis. Apparently office versions cannot. This may (almost definately) be my OCD Kicking in but I’m tired of my stuff all running together. Also completely altering the installed programs might help limit distractions. If that makes any sense. So just Silo-ing by ‘purpose’ or ‘life’ or however you want to refer to it seems easiest. Interestingly my job partition is the easiest to say bye-bye to. Since all the files are in the git repo. Just need to image the base system so I can recover directly.

I was not planning on using the windows backup system. Just use something like EASUS or Acronis to do post install system images, and everything else will just land on the NAS server once it is finished.