Adobe FlashPlayer 1603 Error On Install - How I resolved

I am evaluating the PDQ Deploy product and encountered this error today.  There are a fair number of messages that I reviewed from year's past, but none seemed to apply.  I added a bit to the installer command by customizing the one for IE and added " /L*v c:\temp\flash.log" without the quotes...there is a space before the "/L" argument.  I did this so I could get a verbose log file and put in a folder I could find without searching for the Ark.  Then looking at the file on the client where I was trying to install Flash I found references to older MSI files, version 12 and 15. So, this confirmed for me that I had an issue outside of PDQ Deploy.

I ran the MSI file manually and lo and behold it asked me for an MSI file for version 12 and then for 15.  I followed the steps on Adobe's site for how to uninstall Flash, including running their program and deleting folders (Add/Remove Programs said the programs were not installed).  Oddly, there are no references to the registry.  So I did a search and destroy mission on the registry and found references to the same MSI files under HKEY_CLASSES_ROOT.  I removed all these obviously bad keys and the MSI installer worked manually.  Backed out my customization for the command in PDQ Deploy, and now PDQ Deploy can push FlashPlayer without the dreaded error 1603.

My post on Adobe's site to hopefully help someone else out:

https://forums.adobe.com/message/7189870#7189870