It still functions most times with single click and I can still right click to open the applications. I tried modifying mouse properties (speed) in Control Panel, reloading the Logitech software, using System Restore to go back to a date prior to the problem showing up. Nothing has worked so far. I looked at the Microsoft site and the only reference was to look in the WIN.INI file for (doubleclickheight= & doubleclickwidth= ) but did not even find those lines in the file, so could not adjust them. I have seen some other faint references to Registry fixes and modifications, but am not that well versed or knowledgeable in Registry changes or downloading software to look at possible causes in the Registry. I would try it, but have no experience.
Suggestions would be helpful and appreciated. I posted this a week ago and got no responses.