Thank you for the clarification. The issue is that the HTML popup is loading a PDF file. A PDF file loaded in the browser does not have a DOM structure like a traditional web page, so Test Studio cannot read or verify against its contents. It is also not added to the ActiveBrowser collection, so you can't close it like a normal HTML popup with the ActiveBrowser.Close() code.
The work-around you found in that forum post is a crude way to handle this limitation. We recently made a change to the way coded key presses are interpreted in Test Studio, so I'll check with my developers and see if that affected the AltGr key.
I now do not believe the issue is with the keyboard country layout through the Control Panel (English vs. Italian), but whether the physical keyboard contains the AltGr key. In other words, if you test this with a keyboard without that key (and only the standard Alt key), I believe it will work.
From a higher level, we recommend not even opening the PDF popup because of the limitation previously mentioned. The only reason to open it would be to visually verify that the PDF loads. We came up with an alternative that verifies the PDF URL and returns a response without actually loading it in the window or downloading it:
WebResponse response = request.GetResponse();
"New Coded Step"
//Use the Log line (but not the Assert) if you want the step to always pass,
//yet report a True or False to the log based on response
//Use the Assert line if you want the step to pass if the response is True,
//yet fail if it's False
the Telerik team
Check out Telerik Trainer
, the state of the art learning tool for Telerik products.