Install Visual Studio 2022 on same PC as Compaq Visual Fortran v6.6 2002, continue to run both not concurrently

How to install Visual studio 2022 on a Windows 10 PC keeping active old Compaq Visual Fortran V6.6.

I am running CVF v6.6 on Window 10, maintaining old programs developed several years and wanted to explore recompiling the programs in 64 bit using VStudio + IFORT.

Installed Visual Studio 2022, then tried to run CVF and found that it didn’t run anymore. So uninstalled VS 2022, uninstalled CVF and reinstalled it.

Managed to run CVF once , but only by calling from the command line, and when I tried to run it again a day later it died a few seconds after showing the icon. Looks like the VS 2022 deleted or substituted some files that CVF needs. No error message appears, only the initial Compaq Visual Screen shows for 2-3 seconds and then shuts down.

Any suggestion on how to fix the CVF installation and then how to install VStudio 2022 without this happening again?

CVF has been always been in default path:

C:\Program Files\Microsoft Visual Studio\Common\MSDev98\Bin

Appreciate any help or clue to what’s going on.