I need this snip-it a couple times a year to decompress a folder full of left4dead maps.

You will need, 7zip.

Open a windows command prompt.
cd into the folder where your zip files reside.
run C:\Program Files\7-Zip\7z.exe x *.zip
This will extract all the files into the current directory and retain any directory structure inside the zip files.

Depending on the folder permissions, you may need to start the command window as an administrator.
(right click on the ‘command prompt’ icon and select run as administrator or use the ‘runas’ command.)