How can I get my XBAP to run in my browser instead of downloading it on Windows 7?

Got it... Firefox (and Chrome, since I'm using FF dlls to run XBAPs in Chrome) runs XBAPs by using a dll from the .Net 3.5 Installer, and since Windows 7 comes with 3.5 already installed, this dll isn't available

To fix this, I needed to copy the file

C:\WINDOWS\Microsoft.NET\Framework\v3.5\Windows Presentation Foundation\NPWPF.dll

from an XP machine to

C:\Program Files (x86)\Mozilla Firefox\plugins

(if FireFox folder doesn't exist, create it)

Also in case you're looking to do the same, I think this was the link I used to figure out what FF files I needed to copy to Chrome's installation directory:

The following libraries found in Mozilla Firefox instalation directory C:\Program Files\Mozilla Firefox have to be coppied to Chrome installation directory:

• js3250.dll
• mozcrt19.dll
• nspr4.dll
• nss3.dll
• nssutil3.dll
• plc4.dll
• plds4.dll
• smime3.dll
• sqlite3.dll
• ssl3.dll
• xpcom.dll
• xul.dll

Assumming Chrome is installed in the following directory, USER corresponds to your windows user. C:\Users\[USER]\AppData\Local\Google\Chrome\Application

MIME Type                       Extensionapplication/manifest            .manifestapplication/x-ms-xbap           .xbapapplication/octet-stream        .deployapplication/x-ms-application    .applicationapplication/vnd.ms-xpsdocument  .xpsapplication/xaml+xml            .xaml

Maybe it is related with the file extentsions?