Make sure that 68060.library is installed and that 68040.library has been replaced by the dummy lib from the 68060 archive.
Make sure that workbench.library is version 45 (the one from the OS 3.9 CD). Do not replace it by an older version.
To install OS 3.9 create an emergency disk first and boot from that. Then format your boot partition and choose to install OS 3.9 onto an empty partition.
Bye,
Thomas
