How to bring up PDF embedded in windows.forms.webbrowser control in VISTA

Webbrowser1.Navigate("http://mysite.com/test.pdf")

XP WEBBROWSER-CONTROL: brings up PDF embedded in webbrowser control, as desired.

XP IE7: Behaves the same if you manually navigate to URL, as desired.

VISTA WEBBROWSER-CONTROL: brings up PDF by separately launching Acrobat, won't embed in webbrowser control. Not desired.

Vista IE7: embeds PDF properly if you navigate to same URL, as desired.

I am using Acrobat 9, where there is a preference setting under Internet to bring up PDF embedded in browser -- works fine directly in IE7, but not in webbrowser control.

I want the PDF to come up in the webbrowser control in Vista same as it does on XP and Vista IE7.

I have looked at every property/method/event in webbrowser control and can't find any settings that would matter. I have tried to find some Vista se开发者_StackOverflow社区tting that would be relevant, can't find one.

Platform Target = x86 as to be set. Found answer here: link text

I am using "URL Parameters" as in PDF Open Parameters to get to a certain PDF Page or bookmark. There is something for the layout too. Fineprint: I also do have some issue (see Fragment lost) using it with the WinForm WebBrowser control, nevertheless I find the approach useful (for me it works on Win 7 with .NET 4 except the mentioned issue).