>>Actually, why would it have to open in a browser, default or not? He could just open a new form with browser control in it, and have a report-web-preview inside the app. And open a new instance of this form for every page - or a new tab on that form, whichever suits him better. So the user doesn't leave the app, which I figure creates fewer focus problems.
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>Can i open more than one webpage in a form inside my app at the same time?
>it is an app that user can select some website as favorites and when he/she click on FAVORITES, previous selected address open in separately browser window.

You'd have to add some code to the browser control's navigate or navigate2 method, and check the URL - and if it's not something at the same location as the current URL, just add one more browser control and navigate that one to that URL. You can add browser controls in containers on pages of a pageframe of a form, so you get both the tabbed browsing (less screen clutter for the user) and everything still under your control.