Bypass Windows Vista parental Controls

DO you want to bypass a time limit on Windows Vista Parental Controls? I just had a brilliant idea that doesn't involve hacking or extra software. I have looked around other sites and this methood doesn't appear anywhere. Lets say you are restricted to only use your computer from 4 PM to 5 PM. If it is currently not that time, you can bypass the Windows Vista Parental Controls by simply going into the BIOS at computer startup and changing the master computer time. This will only not work if the BIOS is protected by a password. Microsoft can't do anything about this because their operating system can't control the BIOS.