The activation of the dual boot is a useful “finesse” to try out a new operating system without overwriting. The dual boot of Windows 11 with Windows 10 will allow you to try the latest operating system from Microsoft, without having to resort to virtualization.
All operations should always be performed on systems that are not used for production purposes or in any case after creating a backup copy of the entire contents of the disk or SSD.
Steps to Dual Boot Windows 11 with Windows 10
1) Using the Windows 10 system, generate the ISO file of the latest preview version of Windows 11 by referring to the UUP dumpsite which allows you to download directly from Microsoft official servers.
2) Press Windows + X then choose Disk Management.
Ignoring all the small partitions of a size equal to a few hundred megabytes, you have to right-click on disk C: then select Shrink volume.
3) Making sure to leave enough free space in the partition containing Windows 10 in the Shrink C: window, you must specify a value greater than 64000 in order to allocate enough space for Windows 11 (at least 64 of space). Also plan to leave some free space for the installation of Windows 11 (specify a multiple of 1024 MB).
There is no need to format the volume that will host Windows 11 operating system – you can leave it as unallocated space.
In case Disk Management shows the message ” Unable to shrink a volume beyond the point where any fixed files are located ” we suggest you install and run AOMEI Partition Assistant then choose Resize Partition after right-clicking on the C: drive.
4) After having prepared the space to be allocated to Windows 11, the system must be restarted from the USB drive configured in point 1). Make sure you have correctly set the correct boot sequence in the BIOS (USB first, other drives then).
To access UEFI directly you can press Windows + R then type shutdown / r / fw / f / t 0 and finally use the key combination CTRL + SHIFT + ENTER to run the command with administrator rights.
Alternatively, you can use the command shutdown / r / o / f / t 0 to access the advanced boot menu then select Use a device and finally select the name of the USB drive containing the Windows 11 installation files.
After accepting the license conditions, you must select Custom: Install Windows only then indicate the partition with unallocated space previously prepared.
6) When the installation of Windows 11 is complete, at startup, you can choose whether to start Windows 10 or the new Microsoft operating system.
In case you want to remove Windows 11, just restart the system in Windows 10, use the bcdedit system utility to remove the menu item for starting Windows 11 and then delete its partition with Disk Management.
By right-clicking on the C: drive and selecting Extend disk, you will be able to assign all the unallocated space previously occupied by the Windows 11 partition to Windows 10 again.