ASRock motherboard, pc hangs on xp login screen

My ASRock motherboard is recognising the hard drive, cdrom, ram, floppy but has the cd rom as the main ide drive. It will load to a point but hangs on the xp screen, i have changed the cmos battery with no results, it is saying the cmos settings are incorrect but will not allow me to boot in safe mode or last known good config etc. It will allow me to go to the set up and make adjustments but when I press F9 for load optimal defaults it does not seem to change anything. I am totally at a loss as to what to try next, any help would be greatly appreciated.
Thanks
David
p.s. it will not let me run a cd restore or floppy restore disk either and is sending no power to the usb ports.