As I mentioned in a previous post, Express Install on Windows Vista won’t work on Internet Explorer from a pre-Vista Flash Player ActiveX control. As part of the 9,0,45 launch a couple weeks ago, an update was made to the Express Install error message display.

This update will warn affected users that Express Install won’t work in their configuration, but that they can get Flash Player by visiting the Flash Player Dowload Center. At this point if you have implemented any special checks, you should no longer need them as Express Install will recognize configurations where it will not be able to install.

In case you are wondering what this error message looks like (and don’t feel like uninstalling Flash Player), I’ve included a screen shot below taken from an Express Install experience after uninstalling my current Flash Player and installing that last build of Flash Player 8.

Vista IE express isntall warning

As a reminder, the only way that you will have a user in this situation is if they meet all of the following criteria:

1) Had a pre-Vista (<9,0,28) Flash Player installed on XP
2) Upgraded to Vista from XP
3) Use Internet Explorer 7
4) Attempts to upgrade Flash Player through Express Install

The issue is due to the fact that Windows Vista has a different security model from previous versions of their operating systems. This change requires additional code in the Flash Player installer that uses a broker process to finish the installation. This process is however not required in non-IE browsers like FireFox and Express Install should work as expected.