Playing games outside of steamvr

Hello WMR guru's. I have a question for you all. I'm new to VR and was thinking about picking up hp reverb. I know it will be awhile before they are in stock but the question I have is, I have dcs world standalone version with a lot of modules that won't transfer to steam, so can you play games in wmr just through the desktop or do you have to go through steamvr. Thanks for any help.

@krisguy can you help here?

Yes. If the game is from Steam, you will need to install Steam VR. Windows 10 does not have the ability to use software that isn't designed for it, but Steam VR can piggy-back on WMR.