one way to find if it's Windows problem is see if it will go into BIOS if it will, check plug and play is enabled This will check the keyboard before windows start's to load, if not you have a Hardware problem may be mobo or try another keyboard. Does it say anything about no Mouse etc when starting Comp?
what do you mean by you have disabled the cordless keyboard and mouse? I think you should uninstall any software to do with the keyboards and mice. Then restart the computer with the corded ones connected and windows will load generic drivers for them.
I had a strange problem with my logitech keyboard and mouse, if I install the keyboard first then the mouse won't work.