Are you thinking of Go For Launch: Mercury ? It doesn't look like RE-ENTRY supports VR...Tried it a while back and at least at the time, it felt more like a VR experience showcasing the visuals and the atmosphere (no pun intended) than a genuine systems and/or orbital mechanics simulator.
It's delivered through the Windows Store, and Windows 10 was a free upgrade, so why is that too much?
Nothing new there. They always did this on older machines.
I have an old XP laptop (with no network access):
Windows defender on - can't run anything, hangs and crashes
Windows defender off - runs as new
So disable whatever update is slowing it down.