Q: GPT Error: Windows cannot be installed to this disk

If you are more comfortable using Disk Utility, split it into two parts, and make the first part a FAT partition of any size less than 2TB and the remainder can be formatted as Mac OSX Extended (Journaled).

If you want to use diskutil command line, you can use the following example. Choose sizes as you need. The following command splits the disk disk1 into 2 parts, a 750g FAT32 named BOOTCAMP and remainder as "Macintosh HD" with JHFS+.

diskutil partitionDisk disk1 2 GPT FAT BOOTCAMP 750g JHFS+ "Macintosh HD" R

This is the syntax help for the command.

diskutil partitiondisk

Usage:  diskutil partitionDisk MountPoint|DiskIdentifier|DeviceNode

        [numberOfPartitions] [APM[Format]|MBR[Format]|GPT[Format]]

        [part1Format part1Name part1Size part2Format part2Name part2Size

         part3Format part3Name part3Size ...]

 

(Re)Partition an existing disk.  All volumes on this disk will be destroyed.

Ownership of the affected disk is required.

 

For the partition scheme parameter:

   APM specifies that an Apple Partition Map scheme be created.

   MBR specifies that a DOS-compatible format scheme be created.

   GPT specifies that a GUID Partitioning scheme be created.

APMFormat and APMScheme are synonyms for APM; the same applies to the others.

 

For each partition triplet:

   Format is normally the file system personality used to set the

      partition type and to choose the initialization (newfs) program.

      "diskutil listFilesystems" shows a list of supported personalities.

      Alternatively, you can specify "Free Space" to leave a gap.

      Or you can explicitly specify the partition type (either as a human-

      readable string or as a GPT UUID constant) surrounded by "%".

      Explicitly specifying the type or Free Space implies %noformat% (below).

   Name is the initial volume name (subject to file system-specific naming

      restrictions).  You can also specify %noformat% to skip initialization

      (newfs).  If the format (above) is "Free Space" or an explicit partition

      type, the name is ignored, but it must still be present.

   Size is the length of the partition (slice); the exact resulting size may

      be somewhat larger or smaller as necessary in certain cases.

 

Valid sizes are floating-point numbers with a suffix of B(ytes), S(512-byte-

blocks), K(ilobytes), M(egabytes), G(igabytes), T(erabytes), P(etabytes),

or (%)percentage of the total size of the whole disk; also, at most 1 triplet

can specify a size of "R" (without a preceding number) to specify the remainder

left on the whole disk after considering the other sizes.

 

The last partition will be lengthened to the end of the disk; to specify an

exact size for the last usable partition, specify an additional partition

of type "Free Space".