I have placed ticker on my desktop but it isn't counting down. What do I need to do?

In your ticker html there is a line which tells Active Desktop to update the web page every hour:

<meta http-equiv="refresh" content="3600">

This will only work if your computer is online when it goes to update (Active Desktop really just acts like a browser).
If you normally use your computer off-line, you might need to go online and then right click below the ticker calculator the image (if you click on the image you will get the wrong context menu) and select Refresh to update the image.