Win7 mbr check

[lewmur]

Early on in the Win7 days, I know that people had trouble getting Win7 and Linux to dualboot. I, personally, got into the habit of installing grub in the root partition of the Linux distro and then adding an entry for it in the Windows boot menu.The story at the time was that Win7 had code that checked the MBR during the boot process to see if it had been modified. If so, the boot process terminated. But I can't find any verification for this theory.Just the other day I installed Ubuntu 10.04 on a laptop that already had a dual boot of Vista and Win7 with Vista controlling the bootloader. I goofed and let Ubuntu install grub to the MBR. The resulting grub menu had entry for "Window" which brought up the Vista bootloader with the previous boot menu of Vista or Win7. Both choices would start the proper boot process with the appropriate spash screens. But in both cases, just about the time in the process one would expect the login screen, the screen goes black and the computer reboots.This obviously isn't a problem with the grub entry for Windows and yet the only way to get either Windows OS to boot correctly was to restore the MBR. So, my question is, does Win7, and now Vista, check for a modified MBR and shutdown if one if found? Or is there some other issue that I don't know about?

Edited May 10, 2010 by lewmur

[Guest LilBambi]

This APC HowTo shows you can do it either way: The definitive dual-booting guide: Windows 7, Linux, Vista and XP step-by-step (NOTE: They only show Grub with Ubuntu in the examples)

[lewmur]

This APC HowTo shows you can do it either way: The definitive dual-booting guide: Windows 7, Linux, Vista and XP step-by-step (NOTE: They only show Grub with Ubuntu in the examples)

Thanks, but that doesn't answer my question. I know how to do it. As I said, just install Linux and have it put grub in the Linux root partition. Then add Linux to the Windows boot menu.My question remains. Does Win7 check to see if the MBR has been modified? Simple, yes or no.BTW, the link you gave doesn't give an example of Win7 and Linux.

[Guest LilBambi]

No worries. Sure someone else will have something to say on it.

[Frank Golden]

Hi Lew, it doesn't with my multiboot.In my case when I installed Win 7 on my multiboot (the beta first) it restored the grub mbr to a Windows mbr.I had to dig out my SuperGrub CD and restore grub to sda8, my Intrepid Ubuntu install.I then had a grub boot menu with my normal Windows entry, selecting the Windows entry brings up my Win 7 bootloader from whichI can choose between Win 7 or my XP install.Everything boots normally.I did install Win 7 after I already had a multiboot setup with 4 Linux distros and XP.When I installed Win 7 I created an NTFS partition at the physical end of my drive.I'm thinking you have another issue.