Meteor unable to run on winows

I’ve been using Meteor for a few months now and love it, but yesterday, out of the blue, it just stopped working, for lack of a better phrase. I can create a new meteor project, but every time I try to run, add, delete, etc., I get the same error:
You’re not in a Meteor project directory

To create a new Meteor project:

This error comes up for every meteor project - old and newly downloaded or created (to test if Meteor really isn’t working). I’ve tried reinstalling - as per Windows install/uninstall hell - but nothing seems to work… Help please!

Thank you.