BIOS update has caused me a problem

I can only suggest:
1-Reverse to the previous BIOS.
2-Get rid of that nForce 4 MoBo.

nForce 4 MoBos are hopeless, that's why nVidia sells them dirt cheap. I'd take an ECS Intel Core Logic based MoBo over any nForce 4 MoBo.

Try flashing the BIOS down to an earlier version.

thats the problem i have tried to restore my backup copy, which worked - yet the IDE devices remain undetected????

It might be your cables or a BIOS setting that has the second IDE detection turned off.

try switching ports.

Reset your bios by taking out the battery out of your motherboard leave it out for 5 mins then replace battery then do not go into the bios and touch anything . Once in windows or however you do it reflash your board with the latest bios available and then restart your system then go into bios and select load fail safe defaults then save and exit.

try with just 1 drive then if that fails revert bios

sorted it - uninstalled nForce drivers. reset the CMOS, rebooted installled nForce Sli drivers

wicked

nice, enjoy ^^

Oh thats cool..weldone.