I've a 64 bit Windows 8.1 on GPT / UEFI and am trying to boot to another OS without a CD-ROM or external harddisk.

I've created a fresh partition (Z:) and copied Puppy Linux.iso over to it. However, I can't change the active partition to Z:. diskmgmt.msc's "Mark Partition as Active" is grayed out:

enter image description here

diskpart's active command also doesn't work:

–§–  The selected disk is not a fixed MBR disk.

The ACTIVE command can only be used on fixed MBR disks.

I've also tried both EasyBCD and EasyUEFi, to no avail.

How can we change the boot partition and boot to another OS ?


It's possible, but not certain, that you'll be able to boot the image you copied using my rEFInd boot manager. You can test this without installing anything to your hard disk by downloading the USB flash drive or CD-R image, preparing a boot medium with it, and booting it. If you're lucky, you'll see one or more entries for the Linux kernel(s) and/or the EFI boot loader from the Puppy Linux image you copied to your hard disk, and selecting that image should boot the OS.

That said, installing an OS in this way is highly non-standard, and there are a number of reasons why using rEFInd might not help in your case. I'm not very familiar with Puppy Linux, so I can't say how you're supposed to install it to a hard disk. Skimming its main page, I get the impression that it's intended mainly for use on USB flash drives and CD-R media, although there is one passing reference to installing it to hard disks. If you want to run something from your hard disk, there's a good chance that another distribution would be a better choice.

  • What other distro would be "more compatible" with the approach you are suggesting? I simply need a distro to copy my c: drive (the whole thing, not just the data) onto an external usb harddisk and restore it in a VM in a new computer before i throw away the old computer. – Pacerier May 3 '15 at 9:15
  • For a single use like that, there's no need to permanently install anything; just boot Puppy, Ubuntu, or whatever you like that offers a "live CD" mode and use it from that external medium. – Rod Smith May 3 '15 at 19:15
  • Is dd if=x of=y conv=sync sufficient to work fine? – Pacerier May 8 '15 at 3:04
  • Follow the instructions for whatever distribution you use. – Rod Smith May 8 '15 at 12:49
  • I mean are there any other important flags that I'm missing, or are they optional? – Pacerier May 24 '15 at 15:28

Your system has a UEFI firmware. Because of this, Windows requires you to format your hard drive as a GPT disk instead of an MBR disk (which you have). GPT disks do not have the concept of an "Active" partition the way MBR disks do. That's why the option is grayed out.

In a BIOS world with MBR disks, the computer simply boots to whatever partition has the Active flag on it. In a UEFI world, it's not so simple. To boot an operating system from another partition, you must add a boot entry for it in your EFI partition, and possibly your firmware setup. EasyUEFI looks to be a good tool for doing that, but I've never used it before so I can't vouch for its effectiveness. I have used EasyBCD before, but that tool is not relevant to what you're trying to accomplish.

This brings me to the second point I wanted to make. Even if you manage to get a boot entry for the second partition to appear, you cannot simply drop an ISO file onto a hard drive partition and boot from it. In order to install an operating system, you must have some kind of boot media to install from, whether that be a CD/DVD, external hard drive, or USB flash drive. It's not impossible to install Linux without those things, but it's not a standard way of doing things and there are few tools that can accommodate it (WUBI is a notable example of such a tool).

  • Hi, thanks for the help. Btw, I've already disabled secure boot and enabled legacy (CSM). Will this make it possible, or will it hardly affect anything? Also regarding EasyUEFI, it only allows me to select the "second partition" under "select the target partition" i.stack.imgur.com/SJBah.png . Do you know why that may be the case? – Pacerier May 2 '15 at 1:46

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