Transferring to the Firefox forum in the "Problems with add-ons, plugins or unwanted software" category

In my Control Panel, Uninstall a Program, I have an entry for "Citrix Online Launcher." Do you see anything like that, or if you click the Publisher heading to sort by publisher, anything from Citrix at all?

If not, it's possible the plugin was manually copied to your system or was orphaned when some other software was removed. To physically track down and remove a plugin file, you can do the following:

Type or paste about:plugins in the address bar and press Enter to load the page. Use Find (Ctrl+f) to jump to Citrix and check for the "Path" which should show the precise location on disk. If you can only remove the plugin through physically deleting it, this should point the way to the file.

For comparison, mine's here:

C:\Users\username\AppData\Local\Citrix\Plugins\104\npappdetector.dll

Note: AppData is a hidden folder. If you can't see it, switch Windows over the showing hidden files and folders using the steps in this article: http://windows.microsoft.com/en-us/windows/show-hidden-files

Thanks for the tip. Went to AppData and deleted Citrix folder. End of problem. No more Citrix in PlugIns!