Premier Elements 11 render problem

[Jackchadwick25]

I have recently made a movie using holiday footage and had no problems. I have come to make another and for some reason when i render the movie it makes the quality worse and makes it go pixleated. Anyone know how to fix this please.

[Bill Sprague]

Pixelated during editing or in the final output?  Are you talking about project, preview rendering or output rendering?

[Jackchadwick25]

Hi. So it is fine during editing then once I render it goes pixelated. I have tried exporting to see if it is ok once exported but it is still pixelated. 

[Bill Sprague]

It may be that the source footage, project settings and output (Export) settings don't match.   What are they?