Rodger’s Very Simple Dual Boot Method

Yesterday, I blogged how to add a Windows hard disk to a Linux installation. I noted, it’s relatively easy to add a Linux disk to a Windows installation, and how the Windows MBR gets overwritten by Linux. But it’s harder to add a Windows disk to an existing Linux installation. The whole process with Supergrub was rather complex, and required many slow reboots.

After thinking about it, a much simpler and effective method came to me. And it works!

In a sentence, the trick is to just modify the boot order in the BIOS, and add the Windows disk to grub.conf. Here’s how to do it.

Adding A Windows Hard Disk To A Linux Server

It’s relatively easy to add a Linux disk to a Windows machine. But it’s not as easy to add a Windows disk to a Linux machine.

I have a powerful Linux server that I spent a number of weeks installing software on. When I configured it, I decided to make it a dedicated Linux server. However, a lot of software actually works on Windows. I’ve considered virtual machines. But if you have read my escapades with Virtual Box, a dual boot just makes one less variable and software to be concerned with.

In the past, I’ve created a number of Windows/Linux dual boot machines, and the order of operations was pretty easy. First, install Windows on disk 1. Then install Linux on disk 2. Installing Linux will install grub, update the Master Boot Record (MBR) on disk 1, and give a choice of Windows or Linux when booting.

But this time the order of operations was reversed, and Linux was installed first. Since it took so long to install all the software on Linux, I didn’t want to modify anything on the Linux disk. If there was a problem, I wanted to put it back to the way it was; just remove the Windows disk, and boot Linux as before.

So, the requirements were: Install Windows on a second disk. Get the machine to dual boot, without modifying any of the existing Linux install. Allow for rollback.

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At first, I tried using EasyBCD for a few hours. But I was unable to figure out a solution. On the forums, there were no responses to my question on how to accomplish my task.

Eventually, I got this to work using two methods. The first was to use an older version of SuperGrub. The second method was to use Linux commands. In both cases, I had to get to the Linux OS using either Supergrub, or Supergrub2.