(This is what works for me)
Automatically enter your serial number during installation process.
1.) Create a blank text file using (e.g.) Notepad
2.) Ctrl+c/v or type the following:
CODE
<?xml version="1.0" encoding="utf-8"?>
<Configuration>
<Payload>
<Data key="Serial" protected="0">1234xxxx5678yyyy4321zzzz</Data>
<Data key="Registration">Suppress</Data>
<Data key="EULA">Suppress</Data>
<Data key="Updates">Suppress</Data>
</Payload>
</Configuration>
3.) Save as "application.xml.override"
4.) Put it into "payloads\AdobeMasterCollectionSuiteen_US_volume\" (or equivalent)
5.) Run setup.exe and have fun.
Replace 1234xxxx5678yyyy4321zzzz above with your install code.