Uninstall GRUB boot loader!


Recommended Posts

Is there a way to uninstall the GRUB boot loader either through a live Linux CD or some diagnostic boot CD?

Currently I've used my Toshiba restore disk to reformat my system--removing partitions containing Linux--but unfortunately it didn't do anything to the MBR, so now I have a system that will never load any OS and goes into an endless cycle of reboots whenever I hit the power button.

Any help will be greatly appreciated. Thanks in advance

Link to comment
https://www.neowin.net/forum/topic/426708-uninstall-grub-boot-loader/
Share on other sites

You need to overwrite the boot sector of your partition, and the only way to do that is to use the Recovery Console and run fixboot (not fixmbr). You could also install Windows again, which would recreate the boot sector, but then you'd have an extra Windows installation...

Either way, you'll need a Windows CD, so go find one, even if it's a friend's (Y)

I've always just had to use FIXMBR and had it work every time. However, I'm not sure what you can do if you don't have the CD.

There might be the possibility that you can use a win98 boot disk and do the fixboot command. that might work... not sure...

  Fit4130Rider said:
There might be the possibility that you can use a win98 boot disk and do the fixboot command. that might work... not sure...

No, that won't work. Windows 98 boot disks don't contain ANY NT files, and as such are practically useless on NT/2000/XP machines because they run DOS. The Recovery Console is technically NT, AFAIK.

  John said:

No, that won't work. Windows 98 boot disks don't contain ANY NT files, and as such are practically useless on NT/2000/XP machines because they run DOS. The Recovery Console is technically NT, AFAIK.

I do have a very old Windows NT CD. Maybe that'll work?

Or, alternatively, should I just reinstall a version of linux to get a bootloader and then uninstall the boot loader from within linux? I'd get a "Missing operating system" message the next time I boot, but I've gotten that before and the recovery disk was somehow able to correct that problem.

Again, any help would be greatly appreciated.

You have access to the i386 folder anywhere on your hard disk or a restore cd? from windows start > run > (path to i386 folder)\winnt32.exe /cmdcons will install the recovery console which can be accessed when you next boot. Then remove the grub loader as described above

  Jason He said:

what about just installing Linux and removing the MBR completely from that os? would that work?

I doubt it because you'll be left without a mbr rather than it returning to the original windows one. I think you'll have an easier time finding a copy of windows xp home (i presume)

  the_upsetter said:
I doubt it because you'll be left without a mbr rather than it returning to the original windows one. I think you'll have an easier time finding a copy of windows xp home (i presume)

I am pretty sure that it has to be XP Pro, as XP Home does not include the Recovery Console, so you cannot do the fixmbr thing.

I had a similar problem last night when trying a dual boot with Ubuntu and XP Pro. To fix it, I used a Mandrake install CD to get into the partitioner, blitzed all the linux partitions, setup a temp Linux partition, put Mandrake on (with LILO overwriting GRUB at the mbr) and then used the rescue mode of Mandrake to restore the XP bootloader.

That got me into Windows and then I removed the Linux partition using Partition Magic. Now back to XP Pro (single boot) and no problems whatsoever.

  the_upsetter said:

I doubt it because you'll be left without a mbr rather than it returning to the original windows one. I think you'll have an easier time finding a copy of windows xp home (i presume)

Yes, I would be left without an MBR, but the recovery disk appears to be able to repair it.

You could get a GRUB boot disk in order to get into windows. Then do the C:\ <path to i386> \winnt /cmdcons thing, I've done that and it works. When you reboot, it will need the GRUB boot disk again, and then it will give you the menu for XP or Recovery Console. Log in to the RC, and type fixmbr. Voila, done.

I'm pretty sure grub boot disks can boot to a hard drive, anyway.

And is anyone else wondering why this is in XP Client?

Also, sorry to say this mark, but XP Home does have the RC. I've used it.

There are also RC bootable disks, without the OS on it.

  the_upsetter said:

Does it not? Blimey that's a bit of a loss! Best of luck with the Linux route Jason

I suppose I could borrow a friend's XP Home or Pro CD, but i'd rather do it myself.

The problem was, when I used a SUSE Live CD to uninstall the boot loader, it didn't actually complete the operation. When the YAST2 module loaded to give me access to boot loader options, it said that there was a partitioning problem :rolleyes:

If anyone can boot a Linux LiveCD on a Windows box, they can use the dd command to copy out the MBR boot info (however many bytes that is, 446 or something), then you can use a Linux LiveCD to use the dd command to re-write it to your drive without needing to find any other utiltites.

EDIT: Yes, it is 446 bytes: http://www.diydatarecovery.nl/mbr.htm

The command dd if=/dev/hda of=/dev/hda1/mbr.bin bs=446 should work to read the MBR, and place it in a file called "mbr.bin" in the root directory of your first partition (assuming your LiveCD can write to it). You can pick a floppy or some other device, too.

You would have to get a copy of the MBR from another PC. You could do it yourself, if you have another PC.

Disclaimer: I have *NEVER* tried this personally, so cannot vouch that it will work.

This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Posts

    • The viewing figures in season 2 plummeted after 1 of the main characters died in season 2 episode 1. I think hbo is regretting listening to him so they got rid of him.
    • Google Workspace now lets you use custom AI Gems directly in Docs, Gmail, and more by Paul Hill Google Workspace users can now access Gems from the side panel of Google Docs, Slides, Sheets, Drive, and Gmail. Previously, Gems could only be accessed from the Gemini app directly. For anyone not familiar with Gems, they’re a more advanced feature in Gemini where you can make your own chatbots, powered by Gemini, with custom instructions. If you’re interested in learning more about them, check out my editorial from April, where I argue custom AI bots are the best thing about generative AI and how to create your own bots. The decision to make Gems available across Google Workspace has the potential to significantly speed up people’s workflows if they’ve started using Gems already. If you’ve never made a Gem, Google has several pre-made ones including a Brainstormer, Writing editor, Coding partner, and Learning guide. Google Workspace users can leverage Gems in an almost infinite number of ways. For example, imagine if you’re a teacher in whatever country and you have to make lesson plans for your class that must follow a certain structure, you can use natural language to program a gem to expect certain inputs from you (such as grade, subject, topic etc) and get an output that follows the required guidelines. If you’re a journalist, you could create a gem to quickly strip out the key bits of news from a press release or if you’re a student you can create a bot to break down complicated subjects into something easier to understand. The possibilities are nearly endless and now the Gems you make are even more accessible. Google mentioned that Gems can be accessed via the side panel of all supported Workspace applications and can be used across Workspace capabilities including @ mentioning, accessing files and folders, and more. If you need to create a Gem, you’ll still need to do that on the Gemini website. To get started with Gemini in Google Workspace, just click the “Ask Gemini” (spark button) in the top-right corner. Google said that the Gems feature rollout is an extended rollout which means it might take more than 15 days to get the feature. Admins out there do not need to do anything and there are no specific admin controls in the side panel for Gems or Gemini.
    • Microsoft changes hit Teams Android devices: Disable Entra ID policy to restore sign-in by Paul Hill As part of its Secure Future Initiative, Microsoft has deployed a new Entra ID Conditional Access policy targeting Device Code Flow authentication. Unfortunately, it has led some Microsoft Teams-certified Android devices (Teams Rooms on Android, Teams Phones, Teams Panels, and Teams Displays) to be logged out and signing back in can be a bit fiddly so guidance has been shared. Microsoft said that it shared previous guidance which explained how to exclude Android devices, but it seems some admins didn’t catch this as many devices were not excluded and have been signed out. It’s important to realize that this is not a bug, it’s a security feature. However, the move could have been better communicated. To sign the devices back in, you can do so manually. However, if the devices are remote you’ll need to follow these steps: By disabling the “Block device code flow” policy in step 1, it will change everything back to how it was before Microsoft decided to enable it to boost security. This will allow you to get those affected Android devices logged back in again. Also pay special attention to step 2 which says you might need to reboot your device three times. Once you have your Android devices logged in again, it’s probably a good idea to follow Microsoft’s previous guidance and add these to an exclusion list before re-enabling the “Block device code flow” policy. Microsoft recommends only allowing DCF where it’s absolutely necessary and then blocking it elsewhere. The best thing to do is to add your Teams Android device to the exclusion list - this will allow these devices to operate normally, while boosting overall security. If you’re an admin and have been impacted by this, be sure to take proactive measures to avoid disruptions in the future.
    • Can someone help me with writing a batchfile using notepad to tell me to start a vpn plz? I would greatly appreciate any help  
  • Recent Achievements

    • Reacting Well
      SteveJaye earned a badge
      Reacting Well
    • One Month Later
      MadMung0 earned a badge
      One Month Later
    • One Month Later
      Uranus_enjoyer earned a badge
      One Month Later
    • Week One Done
      Philsl earned a badge
      Week One Done
    • Week One Done
      Jaclidio hoy earned a badge
      Week One Done
  • Popular Contributors

    1. 1
      +primortal
      435
    2. 2
      ATLien_0
      158
    3. 3
      +FloatingFatMan
      146
    4. 4
      Nick H.
      65
    5. 5
      +thexfile
      62
  • Tell a friend

    Love Neowin? Tell a friend!