1. Download MCreator and run EXE installer. If you already have MCreator on C:/Pylo/MCreator, delete folder MCreator.
2. Go to the C:/Pylo/MCreator(version) and run MCreator.exe. You might need to run it as administrator if you get stuck on Building forge or if MCreator setup is complete in less than a minute. In such case, remove MCreator, reinstall it and open with admin rights (right click - > Run as admin).
3. For the first time, you might need to allow the firewall to allow Java access the internet. Setup procedure will start. Wait till it is done (even after you see all ticks, it might take a while before the setup is actually complete) and enjoy using MCreator. You need to have internet access in order to use MCreator.
NOTE: You can install MCreator anywhere (but not in the directory where you already have any files!), but make sure that there are only numbers, English alphabet characters, characters .,-_ and whitespaces in the name of the file path. Other characters from other languages might break the ability of MCreator to work properly.