bad grub on a dual boot Win7 and Ubuntu 11.10 New PC

When I installed Ubuntu 11.10 on my new Windows 7 desktop (Install beside) and tried to reboot, only Win7 would come up. I did the Grub Install procedure but ran it from the Try version of my disk since I could not boot into Ubuntu. This installed a blank GRUB file in Windows. Now I can not get into Windows or Ubuntu except for the demo install. Is there a way to switch from the demo (in Terminal) to the hard disk installed copy file system so I can run Grub Install from the hard disk and repair the MBR in Windows. No Windows software came with the new PC I am attempting to get a copy from the manufacturer,