Fedora 7 keeps locking up

[Les]

Overclocking is a result of a misset bios code.  There is speed control
code in F7 (and FC6) which might cause this, but I don't know the name
of the precise bit of software.  What did you find when you pressed F7?

Is the bios setup correctly?  If not, most bios's have a "reset to
default" capability which can be used to restore the basic setup and
then you can customize it as needed, if you are familiar with BIOS
setups.  Otherwise, you may have misset one of the bus clocking bits or
the cpu frequency.  Was this system working and you just loaded F7 or is
it a virgin system?

Regards,
Les H