How can I stop apps on an external disk from writing on other drives?

Here’s my setup:

  • I have my PC running Windows and an external HDD with apps on it
  • Some of the apps are not portable and save data to places like appdata
  • The apps can change every few months due to updates and changes in what I need at the time

I want to make this external disk fully portable, so I can just plug it into whatever computer I need them on, so I’d like to somehow redirect these file accesses to places on the same drive.

I’ve considered setting up a VM, but I hope I can find a more lightweight alternative. While virtualization is a promising path, my experience with it is limited, so I don’t even know where to start looking.

Some extra details that might help:

  • This is not a security problem, but a portability problem, so the separation doesn’t have to be air-tight.
  • On the other hand, none of the apps need easy access to files outside of their own
  • I’d like to avoid changes to the host computer as much as possible, but I can make changes if necessary
  • The solution only has to work on Windows 11 (possibly Windows 10)
  • I’d like to keep the solution independent from the apps I run, since they change like I mentioned

My #1 priority is ease of use. For example: I start up some environment that runs in the background, but after that I can just start an app when I need to.