Recently Microsoft made the Developer Preview of Windows 8 available for public download and testing. If you are one of the many out there that chose to download it and take it for a spin, you may have run into issues trying to use some of the GoTo products on it.
I have spent some time testing Windows 8 myself and due to the current lack of Java for Windows 8, the easiest work around is to download and install Google’s Chrome browser or Mozilla’s Firefox. When you use either of these browsers to join a GoToMeeting, GoToWebinar or GoToAssist session, they should download an .exe file which you can then choose to open/run. From there the required software should download and install and you will join your session. Remember Windows 8 is currently a preview for Developers, so you should be prepared to run into usability issues like this for the time being.