Silverlight prompts to install often

Using IE 11, Windows 7 Pro - I often get a prompt to install Silverlight. I already have it installed so I uninstall it then reinstall the latest version and then after a few days I get the prompt again.  Sometimes the link to install Silverlight does not work and I have to look up an alternate path to download the software, or switch browsers to download Silverlight.  Sometimes IE prompts to install Silverlight but when I switch to Mozilla, I don't get the prompt for a while - then all of sudden I get the prompt in Mozilla. This becomes very frustrating and a lot of time is wasted trying to find a solution.

Any ideas what the real cause might be? Thanks