I want upgrade my computer

[Sérgio Basto]

Hi, 
I have two machines for test on at home and one at office , I want
upgrade to F18 Beta .


1 - Try Preupgrade but No preupgrade for F17->F18 ?
http://lists.fedoraproject.org/pipermail/test/2012-August/109441.html

http://lists.fedoraproject.org/pipermail/devel/2012-November/173805.html
Why this was disabled 
And what happen if I ignore preupgrade-ok=False

2 - boot.iso, no boot.iso on
http://mirrors.eu.kernel.org/fedora/development/18/x86_64/os/images/
I try one  boot.iso from F18 Beta RC1 and understand why is not there ,
because doesn't work .

3 - Fedup , gives me a Traceback on transaction test. And don't let me
upgrade .

4- use yum but I have bad memories from FC2 about use yum for upgrade 

5- Live iso don't have option to upgrade 

So what you advise me to upgrade my systems ? 


Thanks in advance 
-- 
Sérgio M. B.