Q:

How do I reset MONGO_URL to its default value in meteor?

While trying to run meteor for the first time.. the application struck at 'starting your app'....
I followed this solution.. and did this
set MONGO_URL=''
The application instance started but now
How do I reset the value of MONGO_URL to its default value.i.e. 
I've tried : 
meteor reset  but it doesn't resets the value of MONGO_URL. 

A:

To be clear: meteor reset resets you database files if you are running using the built-in MongoDB. What you want to do unset your shell environment variable. So, assuming you are on windows (because of the solution you linked to):
set MONGO_URL=

(no space or anything after the =)

