I'm getting a popup that a critical update is needed. 5.4.1
when i go to run it i get a fail message saying that it won't run on windows 7 and to please install windows 7 sp1.
I'm on windows 10
Is this what you're seeing?
If so, then that's probably what I see as well. Details here:
https://forums.garmin.com/showthread.php?376548-Garmin-Express-auto-update-does-not-seem-to-work-correctly