SP2 upgrade uncertainty

I last attempted to upgrade my PC to SP2 shortly after SP2 became available. Unbeknownst to me, my pc had a P4 Prescott processor with C0 stepping. When the upgrade permanently locked up my computer, MS disavowed any knowledge of how that could be remotely related to their OS (what else is new).

I have looked into the upgrade once again and have installed kb885626, the update that addresses computers like mine. According to MS, this should allow my pc to accept the update. My question is, do I still need to update the BIOS or should I forge ahead with the SP2 update? Any software that I should deactivate or uninstall prior to the update? What do I need to do to ensure the greatest probablility of success?

TIA

 

Personally, what I find best/easiest is to do a clean install of windows. I install windows, make sure that I have all the drivers I need, then patch windows up fully. Then, I can install my apps, and that will reveal any conflicts they might have with the OS.