Flash Player MSI install does not finish successfully

Hi all

I am having a difficult time trying to figure out why the MSI installer for Flash Player is not finishing on some of our computers I am getting mixed results across multiple machines and I don't feel like I am narrowing it down much.

The problem: when installing Adobe Flash Player using the MSI, Flash will get installed (you can use it and it appears in Control Panel) but the installation gets stuck or something prevents it from finishing. The progress bar will just sit in the middle and Flash doesn't get an entry in Programs and Features. If installing silently (e.g. we use PDQ Deploy) then the installer will never complete and report back to PDQ so it just times out. It will also prevent anything else from installing until you force it to close the installer process via Task Manager or reboot.

The versions I am currently testing with:

• 21.0.0.182
• 21.0.0.242

I have tried:

• Disabling anti-virus
• Uninstalling the anti-virus completely
• Completely uninstalling Flash before reinstalling or installing it on a totally clean Windows installation
  • It also gets stuck when updating an existing installation
• Deploying it silently via PDQ Deploy
  • Whether a user is logged on or not

I get mixed results on different machines. On some I can install it, update it, with or without AV disabled or installed, on other machines it will get stuck on a fresh install. I can't figure out why it works on some and not others. Can anyone think of a reason why this is happening?