Auto Launch ClickOnce App From Web Page

16. June 2014 14:19


Recently ran into a situation where a web page was launching a ClickOnce application automatically (no interaction from the user). This worked fine on a machine running IE8, but not IE9 and greater. It would appear to download the manifest but never actually started the application without user intervention. Some research turned up a MSDN article (see the section on Activating ClickOnce Applications Through Browser Scripting) which indicates the “Automatic prompting for file downloads” under Security/Downloads needs to be enabled. Checked on the IE8 machine and sure enough it was enabled. Went to the IE9 machine, and there is no such setting! After some more researching I found a registry key to change on IE9 and greater to enable the “Automatic prompting for file downloads”:

hkcu\Software\Microsoft\Windows\CurrentVersion\internet Settings\Zones (zone 2 is trusted sites which is relevant for my companies intranet environment).

The key 2200 is Downloads: Automatic prompting for file downloads 0=enable, 3 = disable.


It seemed a reboot was necessary to pick up this change, after which all seemed better.

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I'm a .NET developer, a husband and a father of three beautiful girls.

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