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Author Topic: Converting GPT to MBR Safely  (Read 1489 times)

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Offline Matriplex

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Converting GPT to MBR Safely
« on: February 07, 2014, 04:36:07 AM »
I have Arch and Ubuntu installed on my laptop and I'd like to remove ubuntu in favor of Windows 7 x64. However, when booting up the live disk I made I receive an "Error: could not load boot config files" or something along those lines. So I'm thinking the problem is with my GPT partition table, even though it should support Windows 7 64 bit. So I'd like to convert my GPT table to an MBR table and reinstall grub after Windows installs while keeping my Arch system.

I did some research and found a tool called gdisk, however I'm a little nervous to use it as I don't want it erasing everything.

I have a UEFI motherboard.

Any suggestions?
Thanks

fdisk output:
Code: [Select]
Device           Start          End   Size Type
/dev/sda1         2048     39063551  18.6G Linux filesystem <-- Ubuntu. Yes I know, it's small; see below.
/dev/sda2     39063552     39454719   191M EFI System <-- "/boot"
/dev/sda3     39454720   1229799423 567.6G Microsoft basic data <--partition for Windows to be installed on
/dev/sda4   1229799424   1261256703    15G Linux filesystem <-- "/"
/dev/sda5   1261256704   1937006591 322.2G Linux filesystem <-- "/home"
/dev/sda6   1937006592   1953523711   7.9G Linux swap <-- swap

I deleted my Ubuntu partition previously, forgetting that Grub was preinstalled on it, and I never bothered to put it on a /boot when installing Arch. So I couldn't boot up and just reinstalled Ubuntu on a small partition with Grub on a /boot this time. Just haven't deleted Ubuntu fully yet.
« Last Edit: February 07, 2014, 04:36:48 AM by Matriplex »
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Offline Matriplex

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Re: Converting GPT to MBR Safely
« Reply #1 on: February 08, 2014, 04:46:57 PM »
Hm. I'm not sure about the bump policy on this forum, do tell me if it's unacceptable.
Bump.
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Offline proxx

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Re: Converting GPT to MBR Safely
« Reply #2 on: February 08, 2014, 05:47:35 PM »
Well I suggest you boot a live cd , partion a ntfs drive and a fat32 uefi boot part first part of the drive (iirc)
Than just install windows on the space you already created.
After windows is happy just boot into arch with a live grub that you modified to use the partition on the hdd.
From arch rewrite the uefi partition , its described on the wiki.
Done it on a mac recently, those are the real bitches when it comes to this stuff.
That should be enough.
« Last Edit: February 08, 2014, 05:48:36 PM by proxx »
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Offline Matriplex

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Re: Converting GPT to MBR Safely
« Reply #3 on: February 08, 2014, 09:29:09 PM »
Boot a live cd of Windows, or of Arch?
That's my problem, it won't even boot the windows live cd.
« Last Edit: February 08, 2014, 09:29:21 PM by Matriplex »
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Offline proxx

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Re: Converting GPT to MBR Safely
« Reply #4 on: February 09, 2014, 04:48:43 AM »
Boot a live cd of Windows, or of Arch?
That's my problem, it won't even boot the windows live cd.

Boot linux CD/USB to do partitioning.
Correctly burned cd or USB drive will boot, at least in my case.
You could also use the lve USB/CD to boot the windows cd ;)
« Last Edit: February 09, 2014, 04:52:34 AM by proxx »
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This was another little experiment *evillaughter - Proxx.
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Offline Matriplex

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Re: Converting GPT to MBR Safely
« Reply #5 on: February 09, 2014, 05:07:18 AM »
You could also use the lve USB/CD to boot the windows cd ;)
I've never thought of that, I haven't a clue how to do it either. Thanks for the tip, off to Google :)
« Last Edit: February 09, 2014, 05:07:31 AM by Matriplex »
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Offline proxx

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Re: Converting GPT to MBR Safely
« Reply #6 on: February 09, 2014, 07:05:04 AM »
I've never thought of that, I haven't a clue how to do it either. Thanks for the tip, off to Google :)

Staging a windows boot is well described indeed.
When you find a way that works post it so others might be helped.

« Last Edit: February 09, 2014, 07:05:29 AM by proxx »
Wtf where you thinking with that signature? - Phage.
This was another little experiment *evillaughter - Proxx.
Evilception... - Phage

 



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