Loading Windows from External USB Hard disk

Hello,Before replacing existing system's hard disk with a new hard disk, I am doing some experiments on a spare used hard disk, USB connected.I learned carefully in Macrium knowledgebase.Loaded Macrium Reflect, there are 3 partitions of the system: System Reserve, System (C), and recovery partition.Dragged each one in the same order to the connected hard disk, it took some time, when finished it opened windows file explorer and had a copy of the system on that drive.Restarted computer and tried to boot from that drive - no luck.Did not have enough time to read the error message, computer booted normally (from the normal disk).Any ideas what could be wrong ?Answers will be appreciated.ThanksMotim

Window 10 , 19042.1165, (20H2) x64

If you are booting in UEFI mode, then you need to write the correct BCD to the FAT32 EFI System Partition. You will need to assign a drive letter to both the EFI system partition and the Windows partitions on the USB hard drive. Let's say the system partition gets S: and the Windows partition gets T:. The command would be:

Code:

bcdboot T:\Windows /s S: /f UEFI

If you are booting in legacy BIOS (CSM) mode, it's a little bit more complicated and will require either a Windows 10 ISO file, or a Windows 10 installation USB flash drive.

Is the usb connected HDD recognised in the bios boot menu and if so,was it selected as first boot drive?

joeandmarg0 said:

Is the usb connected HDD recognised in the bios boot menu and if so,was it selected as first boot drive?

Hello and thanks for all the answers.
First, yes, the usb HDD is recognised when booting and I select to boot from it. Please see further.
I tried 3 different methods on a the test hard disk to make it work, all with Macrium Reflect (there was an update recently):One method by dragging the 3 (C:) partitions to the test disk.The second by cloning.The third, I used the real system's backup image to restore it to the test disk.In all the above, first there was "born" a new small disk named "System Reserved (I:)" with two small items in it, then after some time when program finished, the real disk was listed in windows explorer, named "System (H:)".That "born" disk was listed only in the windows file explorer, not as a real disk in the 'Disk Management' window.Checked each time that the small partition "System Reserved" marked as 'Active'.Each time tried to boot from that disk, got an error message ".. Not Accessible..".The backup image is on another disk (in the computer). Every 2 - 3 days I make a new backup, full or differential.I am thinking now: If I install the new hard disk instead of the system disk (same size), then run Macrium ( from resque media) to restore the backup image to the new disk, can it work ?I would like to have your opinions about this. And by the way, In Macrium tutorials there is nothing about that "born" small disk.Answers will be much appreciated.Thanks.MotimWindows 10, 19042.1165, (20H2) x64

Barman58 said:

There is another way that is designed To run a windows OS from an external usb device

Hello,I am afraid I was misunderstood. Actually I do not want a "Windows portable" on usb drive. All the tests I made were to prepare a new HDD to have the system on it and install this new drive replacing the ageing HDD.So after all my tests failed, my question still remains as I wrote before: If I install the new hard disk (empty) instead of the system disk (same size), then boot with rescue media made by Macrium to restore the backup image to the new disk, can it work ?Answers will be appreciated.Thanks.Motim

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joeandmarg0 said:

Is the usb connected HDD recognised in the bios boot menu and if so,was it selected as first boot drive?

Hello,
Sorry for continuing here, but did not want to open a new thread.After all my tests to clone windows on an external HDD usb connected and boot from there failed, I made a deep search in the internet and found in two places listed down that Windows cannot boot from a USB connected drive....I sincerely apologize for bothering you on this subject.So here is my plan, with your permission:In my computer are 3 hard disks,Disk 1 (1TB) with two partitions, C & D. C contains the system and Office and some installed programs, D contains all my portable programs (not installed by setup), some movies and documents.Disk 2 (500 GB) contains pictures, videos and music.Disk 3 (1TB) contains all backups, originals of the portable programs.So I think to remove disk 2 and install instead the new hard disk (1TB). Start and run Macrium to clone whole disk 1 to the new disk. Making adjustments in bios startup menu, trying to start from the new cloned disk. If everything is OK, then connect the original disk 1 in place of removed disk 2, format it and copy all contents from removed disk 2 (usb connected). To have more storage place.I would like to have your opinions about this.The places I found mentioned above1)"https://blog.macrium.com/techie-tuesday-cloning-a-disk-764bed0ad6e1"2)"https://knowledgebase.macrium.com/display/KNOW/Cloning+a+disk"Answers will be much appreciated.ThanksMotimWindows 10, 19042.1165 (20H2) x64

If I were doing this, I connect the new drive I wanted Windows on. Use the standard installation for installing fresh Win 10 on the new drive. It seems you are trying to keep your existing install but do have your files on other drives. Could you just reinstall your software?

Just something to add that has helped me in the past, SATA drives can be hot-swapped. As long as no data is being sent, you can plug and unplug them when machine is on. Just like USB.

@Motim,
Your plan in post #2 is reasonable. However, if you have already cloned disk 1 to the new disk when it was USB connected, you may find that the computer will boot from it once it is installed. One of the standard ways to replace an existing system disk is to connect the new drive to a USB port, clone the installed system drive to the new drive. Then replace the old drive in the computer with the new drive.

Another common method is to create the Macrium Reflect rescue drive on a USB flash drive. Remove the old drive, and install the new drive. Connect the old drive to a USB port, boot the computer from the Macrium Reflect USB flash drive, and then clone the old drive to the new drive.

The third common method is more what you plan to do. Create a backup image of the old drive stored somewhere. Install the new drive. Boot the computer from Macrium Reflect USB flash drive and restore the image to the new drive.

Also, generally SATA drives are NOT hot swappable unless the computer's BIOS specifically supports SATA hot swap. If you hot swap SATA drives without the BIOS support, and the safely remove drive icon in the Windows task bar, you risk corrupting the data on the hard drive when you remove it while it is online.