I'll explain: My PC has two HDD's.
Disk 1 - C: (Windows) and D:
Disk 2 - Z:

I reduced the Z: partition in order to have space for ubuntu. Everything was fine, i installed it, and then it asked me to reboot, so that it would boot ubuntu. It didn't happen, because I have Disk 1 instead of Disk 2 in my boot priorities. When I wanted to boot ubuntu, I just had to select Disk 2, in the Boot menu. No problem. Then, I noticed ubuntu doesn't work on my PC, when i enter login and password, it freezes. It might be my gfx card. So i want to uninstall it, but before i do that, i wanted to clean the MBR, and then format my linux partition. How can i do that? I already tried the FIXMBR command from the WinXP CD, but it didin't work. Any suggestions?

Hi, and welcome to LQ. I suggest you try and bash ubuntu into working rather than just give up, but in the end that's up to you.

I can't recall the exact workings of FIXMBR, but perhaps you (unknowingly) instructed it to work on the wrong drive? Anyways, as long as you have a working bootloader on disk 1 (to test it, take out disk 2 and see if you can boot), there's no harm in having the boot loader on disk 2 as well, and you can't save space by uninstalling it, because the sectors used for it will always be reserved; whether there's a boot loader in them or not doesn't change anything. If you really mean it, you could always just zero out the first couple of sectors (I think "dd if=/dev/zero of=/dev/hdb bs=512 count=10" does the right thing, but I'm not sure; be very sure that it's the right device before doing anything).

hth --Jonas

I want to uninstall GRUB not for saving space. I want to have Disk 2 the same way it was before i installed linux. If i want to install another distro, i think it was better. And in what drive is grub installed? In the linux partition?

Grub is installed wherever you installed it!! I seem to recall that the Ubuntu installer asks you where you want it, but I'm not sure exactly what it says.

Grub (or any boot loader) is typically in the mbr of the first drive (not in a partition).

First, you need to figure out whty FIXMBR doesn't work. Otherwise, you may need to re-install Windows. Make sure your windows drive is #1 and try it again (to be sure, you might even disconnect the other drive).
You can also try something like the Utlimate Boot CD.

In one of my many attempts to setup my system, I just put grub on a floppy---this way the Windows install is never disturbed.

But in teh installer it didn't ask me where to install it, but i know it is in Disk 2, because when i boot Disk 1, it goes to Windows, no questions asked. If I format Disk 2, will it erase GRUB? Or the MBR isn't affected by format?

no, the MBR is not affected by formatting. Use the dd command I gave above, that should clear it out.

I think of formatting as appying to partitions. You can certainly get rid of grub by wiping the drive (Wiping will erase **everything**). You can also use dd--like so:

dd if=/dev/zero of=/dev/<whatever the drive is> bs=446 count=1

Be very careful with dd---it will happily destroy your whole system

and where do i use that command?

in your favorite shell.

In a terminal (command-line)
If you are not familiar with the command-line, then dd might not be the best way to learn.....

The easy way is to download a copy of DBAN (Darik's boot and nuke). This boots from a floppy and will totally erase (wipe) your hard drive. I think it is on sourceforge, but Google will find it.

Hi to all,

I think the easiest way to remove the dual boot is to boot from a Windows 98SE bootdisk and then issue the following command at the A:\> prompt :- "fdisk /mbr". This should remove the dual boot.

warm regards,
Visham

It appears Grub has been installed in the disk 2 and does not affect Windows which has its own MBR in disk 1.

I would just forget about the whole thing of bothering the first 512 bytes of Disk 2 because in installing another OS in Disk 2 it will overwrite its MBR automatically.

However using the Bios to switch the booting order is very old method. One can use Grub or Lilo (the other main Linux boot loader) to do the switching easily. Therefore one can boot to disk 2 permanently and use the boot loader to switch the disk order on-the-fly when booting Windows. All the tips are in the last link of my signature.

It appears to me that you could make Ubuntu by re-configuring Xorg. When Ubuntu hangs it doesn't really hang at all. Pressing crtl+alt+backspace can drop you into the command line mode and there you can look at the Xorg log and re-configure the graphic card.