EvilZone

General Tech => Operating System => Topic started by: Matriplex on February 07, 2014, 04:36:07 AM

Title: Converting GPT to MBR Safely
Post by: Matriplex 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.

Title: Re: Converting GPT to MBR Safely
Post by: Matriplex 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.

Title: Re: Converting GPT to MBR Safely
Post by: proxx 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.

Title: Re: Converting GPT to MBR Safely
Post by: Matriplex 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.

Title: Re: Converting GPT to MBR Safely
Post by: proxx on February 09, 2014, 04:48:43 AM

Quote from: Matriplex 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.

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 ;)

Title: Re: Converting GPT to MBR Safely
Post by: Matriplex on February 09, 2014, 05:07:18 AM

Quote from: proxx on February 09, 2014, 04:48:43 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 :)

Title: Re: Converting GPT to MBR Safely
Post by: proxx on February 09, 2014, 07:05:04 AM

Quote from: Matriplex on February 09, 2014, 05:07:18 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.