Several weeks ago, I had to use System Restore. Since that time, some pages load a screen that is about 6 inches wide by full height. Others open full size. It is not always the same pages that load narrow nor is it always the same pages that load full size. How do I adjust the small screens to stay full size? Thanks for the help!

There are couple tricks to try.

Open two windows, resize the second manually to the size you want. Then close the 2nd window while holding down the Ctrl key. Then close the other window.

If that does not work, try this. Start by closing all IE windows. Then launch IE, right-click on any link, and choose Open in New Window. Size the secondary window the way you want all such windows to be. Now close it by clicking on the X icon at the top-right corner while holding down the Shift key. Repeat this for the primary window that remains. You may have to repeat the process from time to time.