My built-in laptop mouse will not activate desktop icons and will not work at all on desktop. However, it works fine on toolbar icons and on activating the Start menu. Have reduced desktop icons from 25 to 10 but that has not helped. Have restored computer to a month ago state and have completed a virus check but still mouse won't work on desktop area.
Are you running the current drivers for your touchpad? What version of Windows are you using? Normally, Windows Update will install (usually in the optional upgrades area) current drivers for things like mice quite well. You, however, may need to go to your vendor's website and download and manually install yourself.
Another option, is to uninstall the drivers in your Device Manager and then restart your system. Windows will see the change and should re-install your drivers. That may fix your problem as well.