There are two types of disk Basic and Dynamic
Basic partition type A: Master Boot Record (MBR) disk, you can create up to four primary partitions, or up to three primary partitions plus one extended partition. Within an extended partition, you can create multiple logical drives. And the maximum disk size of MBR is 2 TB. If it exceeds 2T, the extra part will be displayed as “unallocated“.
Basic Partition type B: GUID partition table (GPT) disk, you can create up to 128 primary partitions. Since GPT disks do not limit four partitions, you do not have to create extended partitions or logical drives. And GPT has no size limit.
Fix a windows computer that does not boot
In the example above the bootable drive is disk 1
Disk1 is basic disk with MBR
the 600MB system reserved partition is NTFS the windows drive is also NTFS
In windows disk management it is seen as:
Although the C: partition shows boot, but actual master boot record is read from the System reserved partition
It is important that System Reserved partition is Active
if System reserved is deleted or corrupted or does not exist when you have brought your windows files from another disk,
System reserved partition must be created, among many ways , it can be created by diskpart (https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/diskpart)
Since bootrec.exe is a 32 bit program you must boot the computer a recovery disk and use the command prompt of the recovery disk or usb
it can be created by RecoveryDrive.exe from C:\Windows\System32
if there is only one disk
select disk 0
select partition 1
|bootrec /fixmbr||(/FixMbr allows the repair of a corrupted or damaged Master Boot Record. And you should use it when you meet one of these error messages: “Operating System not found”, “Error loading operating system”, “Missing operating system” or “Invalid partition table”.)|
|bcdboot e:\Windows /l en-us /s n: /f ALL||
if your system reserved drive is volume labeled: n
and your windows is on e
Master Boot Record (MBR) is where partitions are defined
The MBR resides at the very beginning of the hard disk and it holds the information on how the logical partitions are organized in the storage device. In addition, the MBR also contains executable code that can scan the partitions for the active OS and load up the boot up code/procedure for the OS.
For a MBR disk (a disk in which the partitions defined in MBR), you can only have four primary partitions. To create more partitions, you can set the fourth partition as the extended partition and you will be able to create more sub-partitions (or logical drives) within it. As MBR uses 32-bit to record the partition, each partition can only go up to a maximum of 2TB in size. This is how a typical MBR disk layout looks like:
GUID Partition Table and UEFI Unified Extensible Firmware Interface
If a model of computer uses UEFI, it will only support GPT.
A GPT (GUID Partition Table) is necessary for UEFI boot records
A GPT can only be used with UEFI boot records in EFI System Partition (ESP) which must be formatted fat32.
GPT makes use of globally unique identifiers (GUID) to define the partition and it is part of the UEFI standard
A choice may be available in the bios to choose the boot mode to be UEFI:
UEFI (Unified Extensible Firmware Interface) stores all the information about initialization and startup in an .efi file. This file is stored on the hard drive inside a special partition called EFI System Partition (ESP). The ESP partition also contains the boot loader programs for the Operating System installed on the computer.
Instead of Master Boot Record (MBR) UEFI stores the information about the hard drive data in the GUID partition table (GPT). The major difference between the two is that MBR uses 32-bit entries in its table which limits the total physical partitions to only 4. Each partition can only be a maximum of 2TB in size, while GPT uses 64-bit entries in its table which dramatically extends the support for size possibilities of the hard drive. (More on difference between MBR and GPT).
The EFI system partition (ESP), a small partition formatted with FAT32, is usually around 100MB, this is where the EFI boot loaders and applications used by the firmware at system during start-up are stored. If your hard drive is in the GUID Partition table (GPT) partition style, it will automatically generate an EFI system partition after you have installed your operating systems.
1. Boot your computer from a Windows installation disc or recovery disk. Press Shift+F10 during the setup to enter the command prompt.
2. Run the commands below to shrink the partition to free up some unallocated space.
▪ list disk
▪select disk X (X represents the disk number of the disk that requires an EFI partition)
▪select partition N (N represents the partition number of the partition that needs shrinking)
▪shrink desired=500 (shrink the partition by 500MB)
3. Then you can create EFI partition out of the 500MB unallocated space using the command below:
▪create partition EFI size=200
▪format quick fs=fat32 label=”System”
▪create partition msr size = 128
4. After those two partitions have been successfully created, use the commands below to install boot loader and other applications needed.
▪bcdboot c:\Windows /s b: /f ALL
Clone: Cloning Hard Disk Drives SSDs:
I suggest using AOMEI Backupper Standard Free,
it works even if the source is bigger than dist but dist has enough space
Before cloning make sure that disk type of the empty destination disk is the same as the source:
Unlike Macrium reflect that stops at the first readdisk error it can be used on a computer where the source and destination are connected as peripherals and copies everything including OS
The professional version is expensive ($50) but might be the sames as others when on sale I saw one as:
AOMEI Backupper Professional + Free Lifetime Upgrade – Lifetime Free Upgrades at CAD 53
Create EFI System Partition (ESP) to Make a GPT bootable disk
– bring up the command prompt.
– Run the following commands at the command prompt.
select disk 0 Note: Select the disk where you want to add the EFI System partition.
select partition 1 Note: Select the partition (# number) or your data partition you want to shrink
shrink desired=900 Note: Shrinks the selected volume to desiredsize in megabytes
create partition efi size=100
format quick fs=fat32
list volume Note: Note the volume letter where the Windows OS is installed.
bcdboot D:\windows /s k:
Note: Replace “D” with the volume letter of the Windows OS partition, k: is your efi partition
BCDBoot copies the boot files from the Windows partition to the EFI System partition and creates the BCD store in the same partition.
To prevent boot problems
In bios disable bluetooth and wwan and other unneeded devices
when low battery plug in do nothing
Graphic card optimization should be set for battery not performance
Not automatic update of manufacturer drivers
bootsect.exe may be needed