Disposable windows installation

Question

I find every few years I re-install windows on my PC for one reason or another eg. I install something which updates the registry and by the time I discover an issue it is too late to roll back.
I can fiddle with fixes but usually after some years it is cleaner to wipe it all and start up again.

For this reason I always partition my disk into 2, C: for Windows and D: for all my own stuff.
But when I re-install, as I've lost the original registry I also need to re-install all my games etc as well (and then pop the save games back from backup).

So it occurred to me, why not install windows on both drives, the D: windows would be passive, except when I install a game - then I boot up on D:, install the game, then reboot on C: again. For windows-related stuff I install on C: and if there is a deep late issue I re-install. Games rarely produce a windows related problem so I would rarely need to re-install on D:.

Now the question is, if you boot on D: and install, then boot on C:, would the game look in the D: windows' registry? Would it work?

Answer 1

Windows does not understand a concurrent windows installation. So the registry hive is located at %WINDIR%, which when booting from C:\ is located at C, and D:\ when booted from D.

That being said, I too have struggled with the same issue as you, and found a pretty good way to counteract it.

If you use Steam and install games through it once to the steam folder, on a new windows install, you only need to install Steam to get your games back.

For applications, I use portable versions of the app. They don't require installation and its settings travel with the program. Just make sure both are located on your D drive, and the only thing you have to do after a reinstall is customize windows to your likings. These can be done by registry exports after you done them, and launching that reg file.

The beauty of this setup is that the programs will still work after you upgrade to a new windows install, and only the customization part may need tweaking. The downside is that a portable program can't update itself usually and requires updating it manually by downloading a new version of that portable program.

If there are a few programs you really want to keep updated, see if they come through a Ninite or PatchMyPC installer. That way, just one exe file installs all your programs.

Answer 2

In a dual-boot setup like you are describing, Windows will use its respective registry and program files depending on which OS you are booting from. This all happens during boot up so it would be very difficult to achieve this. You can make the reinstall process faster by creating and sys prepping a Windows image that you can deploy whenever you need to reload. An article for doing the process is below

https://msdn.microsoft.com/en-us/windows/hardware/commercialize/manufacture/desktop/sysprep--generalize--a-windows-installation

You would basically install a fresh copy of Windows. Enter into audit mode and install all of your apps and make the customizations that you want and then run the sysprep command. It will then remove all of the machine specific data and drivers so that it can be deployed on another workstation. You would then extract that image using the command line on the Windows PE disk and capture the image to a flash drive.

If you need to reinstall Windows, boot to your Windows PE disk, create your partitions, and then deploy your image. Once it restarts you will be presented with the computer setup and once that finishes you will have all of your apps.

This is a little hands on and will likely require a little more research outside of the article above and once the work is done reinstalling is easy.

Josh