Thanks for the tip, I'll give it a shot
I had similar situation.
IE opens up reduced in size when running a web application from VS. I Maximize it using the Maximize button and close it then run VS again then it goes small again.
What worked for me is to manually Stretch it (the browser window) to full size ( Not via the Maximize box, use your mouse and drag it to full size) then closed IE.
I tried again and now it opens in full size again.
Also make sure no JavaScript code doing anything thing to the window size.
When I run my web app via the IDE, it opens up IE maximized (full screen) then when the page gets ready to load it shrinks down my IE window. Is there a way to keep IE to a full screen?