There have been times where I’ve installed Linux on a computer and needed to reinstall Windows. Sometimes I’ve had an issue where after the install gets finished, the installer appears fine but it doesn’t update the MBR (Master Boot Record). So when you reboot the computer you get a Lilo or Grub error saying that the Linux Operating System that it thinks is install is not there.
Before you reinstall Windows, download any of the bootable Linux distro’s such as Fedora Live, Ubuntu or Knoppix and boot into the temporary Linux. Then bring up a Linux shell and type the following. You may need to change hda to your appropriate hard drive device
dd if=/dev/zero of=/dev/hda bs=512 count=1
May 24th, 2010 at 7:52 am
Here are a few other suggestions on how to fix your MBR http://www.cyberciti.biz/faq/linux-how-to-uninstall-grub/