(this was the only suggestion that worked for me)
1) open Terminal
2) type: cd
[always press enter after you type something]
3) type cd /etc/yum.repos.d
4) type sudo nano fedora.repo
the system will ask you to enter your admin password
5) a window will open with the content of the fedora.repo file.
Using the arrow keys, find and replace every https you find to http
(that is, remove the 's' from all https instances, there are 3)
6) press Control-X, agree to save the file as fedora.repo
The window will close
now try again
(I had to do this again with fedora.updates.repo)
Last edited by Yamaplos; 9th February 2012 at 12:30 AM.