I have an idea of what this browser add-on does.
Adobe PDF Browser Control (AcroPDF.dll)
Apparently, if I disable this one, PDFs embedded in a page with the embed or object tag fail to function properly. So, its pretty clear as to its function.
However, I can't find anywhere accurate documentation on what this add-on below does.
Adobe PDF Link Helper (AcroIEHelperShim.dll)
IE9 (with Reader X) seems to work flawlessly with it disabled. PDF's still open within the browser. Only if I uncheck Display PDF in Browser in Readers preferences does that cease. I played around on an XP VM with IE7 and Reader X… no isssues noticed when disabled.
Does anyone know the purpose of this add-on? At one time I believed it was necissary for the 'within browser' functionality to work, though that was never verified. Something change?
Best Answer
According to this link, it launches PDF files within the browser.