Check C:\windows\system32\drivers\etc\ and look for a file called HOSTS (no extension)
Make sure that it contains this line
127.0.0.1 localhost
If it contains this next line comment it out ::1 localhost ( comment is a # in column 1 )
The hosts file is protected by the OS so you must open your editor using "Run as Administrator" or you will not be able to save your changes. Thats by doing Shift + Left Click over your editor icon and selecting the "Run as Administrator" option in the menu that appears.
To configure TeamViewer to not use ports 80 and 443 do the following:-
Start TeamViewer Click Extras -> Options -> Advanced -> Press Show Advanced Options Button -> Scroll down to "Advanced Network Options" Tick the box that says "Dont use incoming port 80 and 443"