Congratz on bumping dude! And also congratz on getting your facts wrong, its usually F8 or F12... but that is not so important....
Oh almost forgot! You wont mess up your windows if you pull the plug, simply because it dont write to the windows files during startup, so no harm will happend ( MAYBE the most harm you can do is to make the newest system restore point bugged... But that is only if your comp writes a new one for each startup (Wich it wont, but that dosent matter

) Or if you are really unlucky and it wanna write a something....)