If you see a dialog such as this one, please make sure to check the 'Allow all applets from "cwmglobalsearch.com" with this signature checkbox and click on the 'Allow' button.
Wait until the applet gets displayed and afterwards click the 'Close Browserwindow' button and proceed with the installation of CWM Global Search.
If you do not see such a dialog the ChemAxon applet is already signed. Wait until the applet gets displayed , click the 'Close Browserwindow' button and proceed with the installation of CWM Global Search.