vrimg files are not associated with any program in Windows by default, they may be associated with the Chaos Group PD Player. Also it doesn’t appear that open with creates an association as expected therefore one may have to use the command line function ftype to achieve the desire association.

The general way to associate files using terminal commands is as follows:

  • Open cmd.exe with administrator rights (right-click on the shortcut to get this option)
  • Type ftype extfile="C:\Program Files (x86)\YourProgram.exe" "%1" where you replace the path with the executable of the program you want to use to open by default this extension (make sure to keep the "%1", this will get replaced dynamically to point to the file you’re double-clicking on) and optionally replace extfile with a name of your choice to describe the type of file you’re trying to open. Then press Enter.
  • Finally, type assoc .ext=extfile where you replace ext by the extension you are trying to associate and extfile with the name you chose above, then press Enter.

So for example to associate .vrimg files with Photoshop 2019 use the following command on a single line each in the Windows Administrator Command Prompt:

first:

ftype vrimg="C:\Program Files\Adobe\Adobe Photoshop CC 2019\Photoshop.exe" "%1"

then:

assoc .vrimg=vrimg

You should now see the .vrimg file have the Photoshop icon associated with them. It may be necessary to reboot or restart File Explorer before the associations show. Note Photoshop can not handle vrimg files natively it requires a third party plugin, I use ProEXR which is now free.