Hello, Frank!
Don't be nervous )
Make next actions:
1. Install Photo! 3D Album from here
http://pho.to/album3d/p3dalbuminst.exe and Photo! 3D Screensaver from here
http://pho.to/screensaver3d/p3dscreensaverinst.exe
2. Then download one of the galleries from here:
http://pho.to/album3d/galleries3d.php
3. Extract .zip file to the .a3g file (right-click on the .zip file -> Extract to the current folder)
4. Right-click on .a3g file -> Open with... -> Choose Program -> and find Photo! 3D Screensaver in a list.
5. Or instead of step 4 you can make right-click on the Photo! 3D Screensaver icon on your desktop, choose configure, then go to the tab "Installed galleries" and click the button Install from disk. In the opened dialog find the .a3g file of the gallery you want to install