Problem with SupportAssist

When I try to run SupportAssist, it says "A task is currently in progress."  I shut down and restarted.  It still does it.  I looked at answers on the forum and followed guidance to uninstall SupportAssist.  However, when I try to reinstall, it says that my SupportAssist is already up to date.  When I click on Windows icon on lower lefthand of screen, it SupportAssist doesn't even show up.  What should I do now?  Thanks.