When the picture pops up, right click on the full size picture, and choose set as wallpaper, or background.
When you click on the screensaver of choice, a download box will appear.
Choose save file to disk, then pick a spot to save the program where you can remember it.
After downloading the file, go to the spot where you saved it in your computer
Double click on the file
choose either, install, or preview. (This will give you a full size preview)
It will now automatically install. If not.
Click start/settings/control panel/display/screen saver.
Click the drop down menu under screen saver.
Find the screensaver of choice and click on it.
After choosing the screen saver, you can adjust the wait time for when it starts.
Check Your Resolutions Size
Click on your start button, on your startup menu.
Move your mouse to the settings tab, and choose control panel.
Double click the display icon, and choose the settings tab at the top of the window that just popped up.
You will see some text that says screen area, with a slider underneath it.
Under the slider it should say 800 x 600 or 1024 x 768 pixels.
You can change it to whatever size you monitor can handle, by moving the slider.