Originally Posted by stevod333
I have tried the DOS command: FDISK /MBR, and WinXP recovery console commands: FIXMBR, FIXBOOT and possibly some others, but nothing seems to be able to erase the MBR to the depth that GRUB installs itself at.
I am sorry that these Windows commands are not working for you, but you probably can't blame it on grub.
Your MBR makes up the first sector (512 bytes) of your harddisk. This first sector is numbered 0. The first 64 sectors of your harddisk are called "track 0". After track 0 is where "normal stuff" begins (your OS, typically).
Of your MBR, the first 442 bytes are called the "boot code". Then the next 4 bytes are the "volume bytes" (used only by newer versions of Windows, AFAIK). The next 64 bytes are called the "partition table". Then the remaining 2 bytes are "signature bytes" that mark the end of a valid MBR.
Installing grub to your MBR will overwrite the 442 bytes of boot code, and put some more data in the (normally unused) sectors 1 through 63. I don't think it goes all the way up to sector 63 - it probably ends significantly before that point.
Running the old msdos FDISK /MBR will overwrite those 442 bytes of boot code with code that should boot any version of Windows AFAIK. It may actually wipe out the first 446 bytes (including the volume bytes), but I can't remember for sure. I do not know why this is not working for you. Just the opposite usually happens. A very standard complaint on these forums is when someone has a working Linux installed, then installs Windows, and wonders where their Linux went. What happened is that Windows overwrote the boot code and thus wiped out grub (or lilo - another Linux bootloader that may be resident in the MBR).
When you run FDISK /MBR note that it does not clear out the part of grub that is in sectors 1 through 63. It doesn't need to. Windows does not use these sectors in track 0. Sectors 1 through 63 may contain nothing, or random data (an old grub install perhaps), and not make one bit of difference to Windows. I know of one sneaky program, Intuit's TurboTax, that installed some code in track 0 a few years back in an ill-conceived attempt at copy protection. This was Intuit's sneaky way to keep their code in place even if you reformatted your disk (format won't touch track 0). However, Intuit shoved it's code into track 0 without concern about what else might already be there. They were wiping out people's Linux grub and lilo installs!
Now back to your problem. I do not know why FDISK /MBR or the other tools you tried would not overwrite the bootcode as they were supposed to. You could use Linux to zero out the bootcode first, and then try your tools again. Assuming your harddisk is "hda", you can clear the bootcode like this:
# dd if=/dev/null of=/dev/hda bs=442 count=1
careful to type this command correctly!!! A minor typo and you can really hose yourself. If you limit yourself to only zeroing the first 442 bytes of track 0, you will leave your partition table intact.