Desktop and Tool bar icons on startup

Hi
On startup a "Zynga" icon appears on my desktop and on my Toolbar and when I press the start button it is there as well.
The program was deleted some time ago, so it does not appear when I click on
Control panel and "Programs and Features"

This means manually deleting or unpin-ing it every day I turn on my computer.
I have asked Zynga but they could not help.

Any ideas on how to delete these, now irritating icons.

Many thanks Tony.

Hi Lemur. Thanks for the reply.
Unfortunately it is not listed.

Not using Firefox?, but Internet explorer and use Google chrome.

Is it in your Startup folder in the programs menu?