Boot camp: "The startup disk cannot be partitioned or restored to a single partition"

Hey All,

Trying to eliminate a bootcamp set up and restore a partition but come up with the above error.

These are the current disk util list specs. Any and all help to avoid a full wipe (although is backed up) would be greatly appreciated!

Thanks

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *1.0 TB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_HFS Macintosh HD 700.0 GB disk0s2

3: Microsoft Reserved 16.8 MB disk0s3

4: Microsoft Basic Data BOOTCAMP 299.4 GB disk0s4

5: Windows Recovery 496.0 MB disk0s5

/dev/disk1 (external, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *2.0 TB disk1

1: EFI EFI 209.7 MB disk1s1

2: Apple_HFS Time Machine Backup 2.0 TB disk1s2