Im Having trouble with Win 2k at startup

Hello all, Im having some problems with windows 2000 at startup. It starts to show that windows is loading when it flips to the blue screen and says it is having trouble loading usbd.sys and portcls.sys from the system32 folder. I tried reinstalling the motherboard drivers and removed most of the hardware devices but it stilll comes up. It gives me a error number but I do not have it in front of me. Anyone with help would be greatly appreciated like if you could tell me what portcls.sys is or usbd.sys controls other than usb items. Thanks and if you need the error code I will get it

thanks