how to start win7 after setting wait time = 0

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http://askubuntu.com – After I installed ubuntu 12.04 LTS. I think waiting a long time to choose between win7 and ubuntu is such a waste. So I went into win7 and set the default to ubuntu and no waiting time(not the grub in ubuntu).Now I can only access ubuntu. But I have something to do with win7. I wonder how can I enter win7? There is no win7 in my grub menu.Even if I add one in, It said no such thing. Since this is win7 I can't edit boot.ini to fix it. I have tried to puch F8 or the down arrow to stop the system turn to ubuntu. But they all failed.I just want to enter win7 and change that damn waiting time. (HowTos)