You need to post your hardware specs, so that it'll be easy to rule out some possibilities.
Also, it's clear that you need to configure the X Window System. When installing, Fedora will try to recognize your graphic card and sometimes uses a generic driver, this could cause the effect you describe.
Type this command in a console (as root):
Quote:
# cat /etc/var/Xorg.0.log | grep "(EE)"
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and post the results.