How to make my old hard drive non-bootable?

Question

Frequently my BIOS for some reason tries to boot to my old hard drive instead of my new SSD. This is starting to get very annoying have to switch hard drive priorities every time I restart my computer.

Disk 0 (Storage E:) is my old hard drive with has GRUB bootloader on it. I want to make that hard drive non-bootable without losing any data on it.

Is this possible?

Solution 1

Your Disk 0 partition 1 (Storage E:) is still has the Active flag enabled.. This is the cause of the problem. You have to remove the active flag from that partition as follows:

1. Open up cmd as administrator.
2. Type diskpart and hit enter
3. Type list disk and enter
4. Type select disk 0 and enter
5. Type list partition and enter
6. Type select partition 1 and enter
7. Type inactive and enter
8. Type exit

Solution 2

This will alter the hard drive to remove the "bootable" flag and empty the mbr. I cannot guarantee success but your bios should skip the hard drive if it doesn't find any boot flag on this hard-drive and no mbr. If used wrongly or under special circumstances this might kill only parts of your mbr or other data, like partition scheme, too, so make a backup before.

1. Boot up a linux. (sorry, dear windows user, search the Web for removing boot flag and dd, dd basically writes zeros to the first 446 bytes which are AFAIK reserved for the Mbr.)
2. Get the /dev/sdX number (probably lsblk or such, I will use /dev/sdh for now)
3. Run fdisk /dev/sdh where sdh is is obviously your right disk.
4. p your partition scheme, look for the partition number (first column, sdXY, ie. sdh6) and if the boot flag (second column) is checked with a *
5. a and then the partition number. NOTE: fdisk doesn't want you to enter sdh6 or even /dev/sdh6, it just wants 6 in this case.
6. p and check the results.
7. w to write changes and exit.
8. Additionally you should empty the mbr

Command to delete mbr only

The following command will erase mbr, but not your partitions:

dd if=/dev/zero of=/dev/sdc bs=446 count=1

Source: http://www.cyberciti.biz/faq/linux-clearing-out-master-boot-record-dd-command/ (not tested, but should work)

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If that doesn't work and the old hard drive is still getting booted, you might try the hack to remove the /boot directory (or empty the partition, if so) on this hard drive. That is the place where the pc looks at boot time and where grub lies. Unfortunately you will loose your kernel (/boot/vmlinuz* mostly) and so but if you really mean to never boot up that device, you can try it. (if you only remove Mbr and bootable flag (or just grub), the boot repair tool can help you. If you delete your kernel and such, you have to reinstall Linux.

Comments

[Jonathan Beaudoin]

Hi, the thing is I used to use the grub booter to dual boot windows/mac osx. I no longer have either of the operating systems so that is why I want to remove the bootable option for that hard disk. I've set my SSD as top priority dozens of times but it keeps resetting, hence why I'd just rather make my SSD the only bootable device in my PC.

[theodorn]

I figured you had tried changing the BIOS, just found it so unlikely that it reverts to the old settings. Just to be sure, did you save the changes before exiting the BIOS? I would make Disk 0 unbootable in GParted - just boot into a live Linux USB. There is a settings called Manage flags, you can uncheck where it says Boot. I've never done this myself, so I can't attest to if it works.

[mivk]

I happened to have this question on a Linux machine, so this was quick and easy. I only needed dd if=/dev/zero of=/dev/$DISK bs=446 count=1. If you do need to check/remove the bootable flag, I would suggest cfdisk which is more comfortable than fdisk.

[DevCompany]

Thank you very much. This has been bothering me for years! Finally a solution to a long time problem Appreciate the clean and concise steps.