Removing Linux From Dual Boot

[halfpower]

I have two hard drives. One with Windows XP and another with Ubuntu Linux. I want to replace Ubuntu with some other Linux distro. I'm afraid that doing this will cause my boot manager to work improperly and that I will no longer be able to access my Windows drive.

I'm trying to use the Windows utility FIXMBR to replace the master boot loader (My terminology might be incorrect. What I am referring to is the little program that allows you to choose which OS gets booted). When I run the utility it tells me that repairing the master boot record could make it impossible to access the two existing partitions on my Windows hard drive. It say something about damaging the partition tables or something.

Do I go through and run FIXMBR anyway? It would be a pain to reload everything. could I just install Gentoo on my Linux drive and hope that Gentoo replaces the master boot loader?

 

[stars]

I believe the message you're getting is default when using fixmbr. You should be fine in using it but be sure to backup any important information just in case. Then install the new distro of choice.

 

[drag]

The fixmbr from recovery console is generally safe. What is not is the old method of fdisk /mbr, which was a undocumented feature of the fdisk utility from the DOS/Win9x days.

fixmbr finds the windows boot loader configuration file from your windows installation partition and rebuilds the MBR from that.

Realise that all the MBR is is the first 512kB of your harddrive, that's all. It's not in a special chip or anything like that, its on the actual drive itself like the rest of your information. The first half of the MBR is your first stage of the bootloader.. At bootup time the BIOS reads that directly into RAM and then executes it. The second half is your partition information.

That's why the command warns you.. because if your harddrive is messed up and it's not booting then writing new information to it may be a mistake, otherwise it's mostly safe.

If your very worried the best thing to do is back up your important information onto DVD or a different computer or something. Another thing to do is you can use the 'dd' command to backup your mbr, then if it gets messed up you can use a boot disk and dd to restore the backed up mbr (from a cdrom or something), but all that shouldn't be nessicary.

When you install Gentoo part of the install should involve installing a new bootloader and then it should detect the windows install and setup the configuration accordingly. Even if it doesn't do it correctly, you can modify the config manually and add the entry for Windows.. it's not very difficult. The only thing that can really mess up is if you accidently delete or overwrite the windows partition. The only thing that can protect you from human error like that, of course, is good backups.