When I do a full screen display on an external monitor with movie studio platinum 9 the image is burly. I am currently using an onboard video card that came with my hp computer. Will upgrading the video card to a Nvidia Geforce 9500 GT solve the problem.
The video card shouldn't make any difference at all. Check your preview mode. There's a dropdown control above the preview display that lets you choose draft/preview/good/best and quarter/half/full/auto. Make sure this is set to preview or good, and full.
When you choose best you will see the quality that you can render but your frame rate will suffer (on the preview only) depending on the strength of your computer (not the video card).
Wow, we sent that comment exactly at the same second! :o)
So, right click on the preview window, preview Device Preferences, and set the Display mode to the secondary screen to "use current settings". Uncheck "scale output to fit display".