Hi, Buzz. I run a laptop with a 1920x1080 LCD. I have to run in windowed mode because of temperature issues if I run full-screen. TS allows you to select a number of different resolutions windowed, but you need to select the one resolution that fills your screen best for your purposes. I found that 1600x900 works best for me, but there are several others you can choose. Trial-and-error will get you to where you want to be. Also, in windowed mode,
you cannot dynamically resize the window. It's fixed at a particular resolution and aspect ratio until you change it in Settings.
Hope this helps!
Best,
Marc