Sometimes the Adobe PDF Reader add-on in Internet Explorer requires disabling and re-enabling. If your Adobe PDF Reader is enabled, but e-forms are still opening outside of the web viewer (you are prompted to download the document), try disabling and re-enabling the add-on. Afterward, close the browser, re-open, and try to open a form in the web viewer in JIDS to determine if this resolved the issue.
For HD Quality click the gear icon in the player and select 720p. Double-click on the video for full-screen: