If the keyboard works fine after you boot from Ubuntu LiveCD(or any other LiveCD really), then the problem might be some deep problem with a really smart Window

If the keyboard works fine after you boot from Ubuntu LiveCD(or any other LiveCD really), then the problem might be some deep problem with a really smart Windows rootkit. That said, I haven't heard of such a rootkit which was able to survive a clean reinstall(it is possible as a proof of concept though). The most likely explanation is a fried keyboard. I used to have the original Microsoft Natural Keyboard that I spilled a drink on, it started doing weird stuff similar to your laptop keyboard afterwards.