You're not supposed to unzip it, and the correct command is:
If you installed Blockland to your Program Files directory:
C:\Program Files\Blockland\Blockland.exe -mod editor
If you installed Blockland to your root directory:
C:\Blockland\Blockland.exe -mod editor
Also, just for future reference, unzipping a folder in Windows is no different than in Mac. You double-click it to open and from there you can copy-paste the files and folders out or you could "extract" (copy) all of the files to one location. The process is not long (whoever told you that was high), but depending on the speed of your computer and/or the size of the zipped folder and the files in it, it might take a while.