During the installation of any of the modern versions of Windows 11 on your computer, the user may encounter a system message "It is impossible to install Windows in partition 1 of disk 0". Usually this situation is observed when the computer already has an OS installed (running on a modern GPT partition table under the UEFI hard disk), while the user tries to install another OS under the MBR on this disk. In this article I will tell you what this message means, what are the reasons for its appearance, and how to get rid of it on your PC.
MBR vs GPT
Before you start using a hard drive, you need to partition it. Information about the hard disk partition table is stored in the "Master Boot Record" MBR (English Master Boot Record), where, in addition to the partition table, there is a part of the executable code and a special signature. The MBR itself is usually located in the first sectors of the hard disk, and without reading the MBR code, further launch of the operating system is, in fact, impossible.
At the same time, the MBR boot record is capable of supporting disks with a volume of no more than 2 terabytes (2.2 Tb), and no more than four main partitions.
But, as you know, nothing stands still, and a new UEFI interface has replaced the outdated BIOS, including an improved GPT standard (English Guid Partition Table – GUID Partition Table). Now each partition on your disk is assigned a unique GUID identifier, and the file allocation system itself on such a disk will be deprived of many MBR restrictions (including the mentioned 2.2 Terabyte disk size limits). The number of possible partitions is also unlimited, while GPT works much faster, allows you to restore previously damaged information and much more.
Reasons for the message "Unable to install Windows 11"
Accordingly, if you already have a disk with GPT under UEFI, and the operating system is already installed on it, then when you try to install a new version of Windows from a disk or USB flash drive under an MBR disk, the system will respond with the already mentioned message "It is impossible to install Windows 11 on disk 0 of partition 1".
At the same time, there are also examples of the opposite, when they try to install an OS under GPT on a disk under MBR. Then the system will indicate that installing a new OS on the disk is not possible, since it already has an MBR partition table.
Accordingly, the OS installation conflict under MBR — GBT will be the cause of the error with the inability to install Windows 11 OS in partition 1 of disk 0.
How to fix the problem "It is impossible to install Windows in partition 1 of disk 0"
So, how to fix this error? There are two main ways:
We delete all the partitions on the disk, and then create them again under the MBR. With this method, the data on the deleted disks will be lost, and a disk with an MBR partition table will be created.
To do the above, click on "Disk Setup" when installing Windows, delete the hard disk partitions, and then create them again (they will be created already under MBR).
At the same time, it is worth considering that if you have a disk with a volume of more than 2.2 Tb, then the system can re-create a GPT table on the disk.
An alternative, but more complex, option is to use the utility to work with diskpart disks. To implement this option, boot from the installation flash drive (or disk), select the language, click on the "Next" button. Then select "Install", then "I accept the terms of the agreement" — "Next" — "Full installation".
Then press Shift + F10 (for laptops Fn + Shift + F10), which will launch the command prompt. In it, type the following commands sequentially, without forgetting to press enter after each command:
list disk (displays a list of disks)
select disk 0 (instead of "0" there may be another digit of the desired disk, if there is one disk, then it is 0);
clean (cleans the disk from other partitions)
convert mbr (converts GPT disk to MBR)
After executing these commands, you can usually continue installing the OS already on the disk with the existing MBR table.
In the question of how to get rid of the message "It is impossible to install Windows 11 in partition 1 of disk 0", it is necessary to proceed from understanding the MBR-GBT conflict, and install a new OS immediately under GBT, or clear the existing disk partitions, create an MBR, and only then install a new OS under MBR. This will help to avoid the appearance of the message I am considering, and install a new operating system on your PC without any problems.