stop and remove nginx from win7

Ok well first of all i really have no clue what i am doing, i wanted to install nginx to make a livestream and now i'm just lost. I downloaded everything i found on nginx for windows and somehow managed to create 2 extra users at win login and i don't have the password, and overall i never really did learn what i was doing. Now i want to try again but this time in a virtual machine so i don't screw up my OS, but first, i need to get rid of nginx in windows. I've tried using the nginx stop shortcut (i dont even know how to open nginx in a cmd window) in the nginx folder but it requires me to have a password and i don't think i never did set up one, and lost the default.
How can i get around this? what is the default password? if there is no default password is there a way to recover mine? any other way to completely remove nginx from windows?
Any help truly appreciated :) , i feel like i have a lot of learning to do before i can make my little project work.