DiskPart Format : Parameter is incorrect

Question

I am trying to format a virtual disk & I get an error. I have selected the partition to operate on & ran the format command in a variety of ways [recommended, ntfs, fat, also combined with quick].
I can't for the life of me figure out whats wrong. Is it that DiskParted is bugged here? or am I missing something?
This issue happens in Windows 8.1 & Windows 10 Beta. Never tried 7, but I assume the same would occur
DISKPART> list disk
Disk ### Status Size Free Dyn Gpt
Disk 0 Online 167 GB 1024 KB
Disk 1 No Media 0 B 0 B
* Disk 2 Online 200 MB 0 B
DISKPART> list partition
Partition ### Type Size Offset
* Partition 1 Primary 198 MB 64 KB
DISKPART> format fs=ntfs unit=4096 quick
0 percent completed
DiskPart has encountered an error: The parameter is incorrect.
See the System Event Log for more information.
DISKPART> format recommended
0 percent completed
DiskPart has encountered an error: The parameter is incorrect.
See the System Event Log for more information.

Answer 1

Hi RandomClown,
Format command could be used directly from the CMD Window, no need to under the Diskpart Session.
You may try to format in this way:
format <Volume> [/fs:{FAT|FAT32|NTFS}] [/v:<Label>] [/q] [/a:<UnitSize>] [/c] [/x] [/p:<Passes>]
More information, please check:
Format
To use the Diskpart command, we need first select(not the list command, use the select command) the disk that we want to format, for example,
To use the command line to bring a disk online, create a partition, and format it, you may try the following commands:
C:\> Diskpart
DISKPART> list disk
DISKPART> select disk (id)
DISKPART> online disk (if the disk is not online)
DISKPART> attributes disk clear readonly
DISKPART> clean
DISKPART> convert mbr (or gpt)
DISKPART> create partition primary
DISKPART> select part 1
DISKPART> active (if this is the boot partition)
DISKPART> format fs=ntfs label=(name) quick
DISKPART> assign letter (letter)
DISKPART> list volume
More information about Diskpart command, please see:
DiskPart Commands.
Best regards
Michael Shao
TechNet Community Support