Vbnet2012- pdf viewer control doesn't work, why?

Hi guys,

with my VB2008 ver I did some simple code that loads a pdf into a pdf viewer with "AxAcroPDF1" command and it worked fine, but with my VB NET 2012
it returns error ,why?
Does anyone have an example of opening a pdf file into this "AxAcroPDF1" command from a specific location in the computer? in VB NET 2012

thanks