Windows 11 into one and only partition. Is that possible?

Hi.


I want to know if it is possible to instal win11 to one and only partition without any extra and mostly at old pc's without uefi bios.

Please tell me if it is possible to old and new pc's install win11 to one and only partition.

yes.

for bios boot it is quite common for one partition to be both system and boot.

that means one partition is marked active and windows is installed to that same partition.

It should be straightforward:
initialize the disk to mbr
create a partition and format it ntfs.
mark the partition active.
point windows setup at that partition when it asks where you want to install windows.

It is easiest if there arent any other disks attached during installtion.

( It can be done for efi boot if the bios supports efi booting from ntfs, only some do so is not very common )

So the only way to make clean install of windows 11 to a pc(even old without tpm or uefi) is to install it to an active formated partition.
Correct?
Isn't there any other way to make a win11 clean install to an unformated hdd and don't create any extra partition?

For example if i put a switch to the install command?

For example if i put a switch to the install command?

Click to expand...

not that I know of.

windows setup will use the existing active partition to deposit the boot critical files.

If there isn't already an active partition, it will create a separate system partition.

I dont think I have tested with win11 to see if it tries to create a recovery partition in that scenario..

So there isn't any way to make win11 clean install not create any extra partition????
Only if i install it to an active already formatted partition.

I can vaguely recall some hex editing of windows 7 setup files to stop it from creating the system partition. Havent heard of anybody doing it recently.

you might be able to set it up with an unattend file. I dont know much about the unattend stuff in win11, somebody else may be able to advise.

Gregory, let me ask a question:

How important is this to you? Here is why I ask...

I often offer to perform testing for someone, go through several hours of tests, post a response, and never ever hear back from that person.

Bottom line is that I have the knowledge to make this work - if it is possible. The "if it is possible" is the only question mark for me. I'm willing to test this, but only if I know that it will really help you .

Some more info...

On a UEFI based system, you would normally have 4 partitions. On legacy BIOS, as is your situation, you would have 2 partitions: the Windows partition and a System Reserved partition. I can easily create an installation that forces Windows to create only a single partition, omitting the reserved partition, to see if it will work.

But I want to know that this going to really help you before I make all that effort.

Before we go any further, can I inquire why you even want to do this? The reserved partition is only ~500MB in size so if space savings is the concern, it seems hardly worth the effort to me. If you have some other concern, let me know what that is and possibly I can make some other recommendation that satisfies your needs.

EDIT: One additional note - for UEFI based systems, forget about it. It's not going to happen .

hsehestedt said:

EDIT: One additional note - for UEFI based systems, forget about it. It's not going to happen .

Click to expand...

Some UEFI systems can boot from an NTFS partition, and on those systems it would be possible.

NavyLCDR said:

Some UEFI systems can boot from an NTFS partition, and on those systems it would be possible.

Click to expand...

Thanks for the clarification. I guess I could test that as well, although I am still at a loss as to how this might be useful.

SIW2 said:

yes.

for bios boot it is quite common for one partition to be both system and boot.

that means one partition is marked active and windows is installed to that same partition.

It should be straightforward:
initialize the disk to mbr
create a partition and format it ntfs.
mark the partition active.
point windows setup at that partition when it asks where you want to install windows.

It is easiest if there arent any other disks attached during installtion.

( It can be done for efi boot if the bios supports efi booting from ntfs, only some do so is not very common )

Click to expand...

post #2

to test it with unattend file would need a machine with bios that supports efi boot from ntfs.

hsehestedt said:

Thanks for the clarification. I guess I could test that as well, although I am still at a loss as to how this might be useful.

Click to expand...

To satisfy someone's OCD would be the only reason I can think of.

Guide, how to install Windows 11 on unsupported computers in Legacy BIOS mode in a single NTFS partition (without the small system partition). I do that on system with very small storage such as 64GB or 120/128GB SSD to get the maximum possible disk space.

Create a hybrid Windows 10/11 USB flash drive or a Rufus patched Windows 11 USB flash drive. The first is a regular Windows 10 64-bit USB flash drive (created for MBR, Legacy BIOS mode) with the file sources\install.wim (or install.esd) replaced by the respective file from Windows 11 ISO. In the second case Rufus creates the USB flash drive and patches some files to bypass compatibility check.
In either case boot with the USB flash drive and at first screen press SHIFT+F10 to open a command prompt. Type the following code, press ENTER after each line to execute:
WARNING: All data will be deleted from the target disk!
This code selects your hard disk (usually disk 0, change number as needed), wipes all data and creates a single NTFS partition. Then it exits diskpart and finally closes thet command prompt. You may then proceed. When presented with the disk click on it and proceed, don't change anything.

Tip: To avoid using a Microsoft account and create a local account instead, do not connect to the internet. At the account setup press SHIFT+F10 to open a command prompt again and execute the command OOBE\BYPASSNRO. This will restart the computer and go through the initial configuration again, but this time you will see "I don't have an internet connection". Click on that to create a local account.