Cant open files on Adobe Premiere Elements

I have installed Adobe Premiere Elements 7 onto our current laptop.  It was previously used on our old pc.  I have digistised old videos as mpeg files on our current laptop and I wanted to start editing in Adobe.  When I select the files for editing a message box tells me "I must activate this component in order to use this feature" and I must click on a link w.adobe.com/go/enco deactivation, copy the MPEG2 component serial no. listed and get an unlock key, to proceed further.  The link doens't work. 

When I cancel out of this message box, another box says "Add media failure", and says "This type of file is file is not supported, or the required codec is not installed"

Not sure how to proceed from here.