What plug in? Most have installers.
Did you do a standard install of AE?
if there is no Adobe AE folder in your program folder then you are either not looking in the right place or you somehow fouled up the installation.
What OS and version of AE are you using down to the last decimal point? Take a screenshot of the application folder and drag it to the reply field on this forum or print screen and paste. If you cannot find AE you should be able to reveal it with a search of your folders.
The plug in is AE Pixel Sorter
I don't understand how to not do a standard install of AE...I use the Creative Cloud dock, and yesterday I updated to CC 2017.
I don't know how I might have fouled up the installation either, considering I didn't do anything different than I have with any of the other apps. Photoshop, Illustrator, InDesign, etc have folders within the Program Files location. Apparently instead of placing the file in Program Files my computer put AE in my documents. So I now have that located - but within the folders there is no Plug-in folder.
I'm running on Windows 7 and AE 14.1
Did you ever install this plug-in? If not, please let us know. Perhaps we can assist you.