Bootcamp "The startup disk cannot be partitioned or restored to a single partition" error.

T0W0 wrote:

I am almost afraid to ask, but could you help me?

You do not need to be afraid, anymore!

T0W0 wrote:

Thanks already for reading

Every EFI NO NAME indicates a failed attempt during installation of Windows, with an external storage unit connected. Can you reboot so the disk slices get ordered correctly?

You have an 'inverted' layout. What is the year/model of your Mac (do not post the serial number)? Do you have a Time Machine backup of macOS? I also suggest starting a new discussion, to avoid confusion.

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *1.0 TB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_APFS Container disk1 898.0 GB disk0s2

3: Microsoft Basic Data 101.5 GB disk0s3

4: Apple_HFS 492.8 MB disk0s4

/dev/disk1 (synthesized):

#: TYPE NAME SIZE IDENTIFIER

0: APFS Container Scheme - +898.0 GB disk1

Physical Store disk0s2

1: APFS Volume 455.9 GB disk1s1

2: APFS Volume 42.9 MB disk1s2

3: APFS Volume 512.4 MB disk1s3

4: APFS Volume 4.3 GB disk1s4

Proteinz wrote:

/dev/disk0 (internal, physical):

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:      GUID_partition_scheme                        *3.0 TB     disk0

   1:                        EFI EFI                     209.7 MB   disk0s1

   2:                 Apple_APFS Container disk2         2.5 TB     disk0s2

   3:       Microsoft Basic Data BOOTCAMP                501.3 GB   disk0s3

   4:           Windows Recovery                         505.4 MB   disk0s4

If you see the highlighted line when you run the diskutil list command, you are ready to eraseVolume disk0s4.

What is "Data" used for? Do you have a back up of macOS?

Macintosh HD is part of an APFS container. If you need to increase it's size, we also need to temporarily remove Data. Do you have a full backup of Data?

Please remember to backup macOS, before re-attempt Windows installation. If it is an iMac, please run a SMC and NVRAM reset as well.

Do you have a 3TB Fusion drive iMac? Splitting the Fusion drive into the underlying physical disks can cause issues.

Please start a new discussion, and post the output of

diskutil list

diskutil cs list

Your issue is unrelated to this discussion.

How did you create the Windows partition before the macOS APFS container? This is a non-standard partition layout.

Are you using a Beta release of macOS, or did you install a Beta release on this Mac at any point in time in the past? The Kernel Core dump file system should not be there.

See Re: Bootcamp - unable to remove Bootcamp partition .

Can you start a new discussion, and post this output? Your problem is not the same as the issues on this discussion.

sumaia111 wrote:

What should I do?

Can you post the current state of the partitions using diskutil list?

Run BC Assistant, and click on Remove/Restore. It will remove the current disk0s3 and put the space back into macOS partition.