Detect from browser if specific application is installed

Question

We have an advanced webpage (ASP.NET, C#), and a application which needs to be installed on the client computer in order to utilize the webpage to its fullest. The applicati

Answer 1

If you want to detect with javascript inside the browser, you can probably use the collection "navigator.plugins". It works with Firefox, Opera and Chrome but unfortunately not with IE.

Update: In FF, Opera and Chrome you can test it easily like this:

if (navigator.plugins["Adobe Acrobat"]) {
// do some stuff if it is installed
} else {
// do some other stuff if its not installed
}

Update #2: If it is an ActiveX object in IE you can test if it exists by using something like this:

function getActiveXObject(name){
        try{
            return new ActiveXObject(name);
        }
        catch(err){
            return undefined;
        }
};

Another approach for IE is something similar to what JohnFx suggested (I found it here and have not tested it):

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\Internet
Settings\User Agent\Post Platform