whenever I'm running commands like firebase login, firebase init the error at command prompt appears that
Error: EEXIST: file already exists, mkdir 'C:\Users\UserName.config\configstore'
I would suspect that some other application or tool is also using using the configstore folder to store their files, and the
configstore module that the firebase-tools is using is throwing an error because it tried to recreate the folder when it was already there. An exception being thrown that they did not handle correctly.
This happens a lot and personally is a huge annoyance to me. I do not understand why they use such a generic file name to store their config with the chance that another program will do the same.
Anyways, all my complaints aside, try opening up some of the files in that
configstore folder in a text editor and see if you can see what other program is using them. If it is something you don't use anymore, simply remove it. If it is, then you might have a bigger problem. If that's the case, you would have to either pick which program/tool to use, or find a way to change where it looks for it's configuration files. I personally know for sure that bower uses this same exact directory for it's config files.
Hope this helps. It's a frustrating thing when two applications collide over something so easily preventable.