Update Free AVG

I am having a problem with updating the free version of AVG.  It won't let the update finish.  I've restarted my computer numerous times, & it still won't update.  I can't even get the AVG to do a scan of my computer.  I tried to uninstall it thinking if I reinstalled, it would fix whatever problem there is.  However, it won't even allow me to uninstall it.  Very frustrating!