Hi on starting the computer it gives the F1 option if you press F1 says entering setup, but does not just continues till after the battery warning then gives F1 for setup again or esc to boot which works, does not ask for a password just refuses to enter setup I have not seen a bad cmos battery stop you getting into the bios, but I'm thinking this is the only option left. The battery is part of the timer chip and is soldered onto the board, I'm going to have to unsolder this and replace it. There is a video on youtube showing how to disable the old battery and fit a cr2032 holder on top of the chip, but this involves cutting into the side of the chip to access the pins you attach the new battery to, a bit daunting don't you think? this may sort it, but we'll see. Thanks for your suggestions cheers Robbie.