I am my wits end. After happily using Fedora 12 for several years, I decided it was time to upgrade. So, I bought a new computer three weeks ago and have been trying to install Fedora 20 ever since, with always the same eventual result. The vendor installed Windows xp3 for me, and I am using it for this posting. I have no trouble at all with dual boot and the Windows installation, including Internet access, and my two laptops and Motorola Milestone 2 mobile phone are all ok with the 'net in my house, they are wireless, this computer is on a wired connection, to a BT Home Hub 3 router.
I have just tried, yet again, to install Fedora 20 from a DVD (full not live). At the "installation complete" message I ejected the DVD ready to re-boot, but the screen went blank and in the end I powered it down and turned it on again. I re-booted again from the screen because everything was very slow at first.
Then I encountered exactly the same problem as before, I try
yum install emacs, which is my favourite editor, and got the result in the image. If Ihad left it running I would have got the usual streams (up to 200 or so) of the "trying other mirror" before it returns to the prompt.
I have installation DVDs, from the same supplier, for F17 and F19, I have tried them all with the same result.
My problems all seem to be with the Internet in Fedora. However, using the default internet browser in the installed Fedora, most searches work after I try them twice in succession. And, of course, no Internet problems at all with the dual boot Windows on the same machine. I saved the image attached from Linux to Windows with no trouble, using the graphics listing application (is it "Dolphin" -- brain fuzzy) in Fedora.
Just to make it completely clear, the only problem I have with the Internet is in my newly installed Fedora 20: the Windows XP3 in its partition on the same computer is completely ok.
All that is different from my old F12 set up is a new computer and my Fedora installation. Please, what am I doing wrong? I hope that this is a recognised problem with a straightforward answer.
Thanks for the kind suggestions. I am now getting the error "Cannot retrieve metalink for repository: fedora/20/i386. Please verify its path and try again". A web search shows this to be very common, with as many different answers as questions. None of them, those I can make sense of anyway, work for me.
What is really needed is a diagnostic procedure that will lead to the underlying fault, and to a solution. Where can I find such a procedure, does it exist?