[BLURRYFΛCE]

How does one dual-boot Debian Wheezy & Windows 8.1 /w Debian Wheezy installed first?

[Tirus]

You need to select the partition you wish to install Windows on with a specific size you wish the Windows drive to be.

[BLURRYFΛCE]

You need to select the partition you wish to install Windows on with a specific size you wish the Windows drive to be.

Yes, but how to deal with the fact that the Windows bootloader will overwrite the GRUB bootloader? Also, the Debian Wheezy install is LVM encrypted with dm-crypt, any specific details I need to know as to how to re-construct the GRUB bootloader after installing Windows?

[Betty Blue]

Yes, but how to deal with the fact that the Windows bootloader will overwrite the GRUB bootloader? Also, the Debian Wheezy install is LVM encrypted with dm-crypt, any specific details I need to know as to how to re-construct the GRUB bootloader after installing Windows?

It is preferable to install Windows first. But if you can't, just install Windows and then install GRUB again.

[BLURRYFΛCE]

It is preferable to install Windows first. But if you can't, just install Windows and then install GRUB again.

How does one go towards doing such?

[Betty Blue]

How does one go towards doing such?

Balls. I forget the exact steps to do it.
You could probably use the Debian disk you used for Wheezy and then skip all the steps except 'Install and Add Grub to the MBR'.

[MoonCakeRuler]

I had the same problem with my laptop, which came with Ubuntu and I had to install Windows on a different partition. I ran into it once before so I was able to fix it by chrooting into the installed Ubuntu and then installing/updating grub there. The steps are kinda like this.

Boot using whatever live media you have. Open a terminal and type the following, use sudo or just go root.

First, mount the partition where Debian is installed. Let's say you have your root filesystem on /dev/sda1. You can do it with:

Code

mount /dev/sda1 /mnt

/mnt is where it's being mounted, you can change it of course.

Next, you need to bind mount the /dev, /run, /sys and /proc directories, as they need to be populated manually. Bind mounts basically mount a path to another instead of mounting a device with a FS.

Code

mount --bind /dev /mnt/dev
mount --bind /run /mnt/run
mount --bind /sys /mnt/sys
mount --bind /proc /mnt/proc

I think a loop would do as well, but let's just play it safe for now xD

Next, chroot into the mounted system.

Code

chroot /mnt

You should be inside your installed Debian right now. From here just update/install grub. Here take care to install it to /dev/sda, not to /dev/sda1.

Code

$ grub-install /dev/sda
$ update-grub

That should re-install grub. Exit from the chroot with 'exit' and then unmount everything using 'umount'.

Code

umount /mnt

Then just re-start your machine and your grub should be back. This has kinda stuck to me because I've done it twice for me personally and for a few friends of mine who got into the same sticky situation.

However, just be careful with the partitions. There isn't much to screw up if you're careful but still it may lead to data loss if you mess up.

Hope that helps. There are other solutions using Rescue disks and so on I assume but this has kinda worked out for me so I hope it works out for you as well. If it doesn't, oh well. xD