Recently someone using a computer of mine started a remote session with GoToMeeting and allowed someone to control the PC. UAC didn't block the session (they're a regular user). It appears that many of the remote access tools ignore UAC and regular users can invite anyone to control the PC.
Are there any methods of blocking tools like GoToMeeting, join.me or TeamViewer on a regular Windows 7 PC?
So far the only thing that seems feasible is blocking the websites serving up these tools, but there are easy ways around that.
Many of these tools seem to dynamically use ports that are open, so port blocking doesn't seem feasible either, but I might be wrong.
Best Answer
All of these services rely on connecting to the service provider (e.g. GoToMeeting) before the other party can connect to you. As such, you should be fairly successful by simply blocking their domains on your router. Even inexpensive home routers support this feature.
As an example, take a look at the "Website Filter" page on a $20 D-Link router. In each of the boxes you would enter domains such as gotomeeting.com, joingotomeeting.com, join.me, etc.
If I find a pre-compiled list of these, I will make sure to update this post.