First - hit the keyboard function key F11. This toggles the window to full screen mode. You can toggle back and forth between normal and full screen modes at any time in Windows using the F11 key. A useful feature.
Second - change the monitor resolution to 1024 x 768 pixels if isn't already there. To do this, go to the desktop and right click on it. In the window that opens, click "Properties" at the bottom. In the display properties window that opens, click the "Settings" tab. Half way down, on the left is a slider marked Screen Resolution. Right below the slider are a pair of numbers like 800 by 600 or 1024 by 768 or 1280 by 1024 pixels. There may be other possibilities as well. Make note of the current setting (both numbers) so that you can restore it later using the same procedure.

Now, move the slider left or right until it reads 1024 by 768. Make sure both numbers are correct, and that you're not exceeding the capability of your monitor, then click "Apply". Your monitor will switch to the new resolution. If you wish, you can restore the original resolution later using the same procedure.

You're now ready to enter the gallery. Enjoy!
Monitor - Full Screen vs Normal Mode
Monitor - Screen Resolution