We can use the below commands to delete a user account using windows command prompt.
To delete a user account of the local system:
net user username /DELETE
To delete a user account from domain:
net user username /DELETE /DOMAIN
You need to have domain administrator privileges to perform this operation. Note that we do not need to specify the domain name in this command.
The above commands work on Windows 7, Windows 8, XP and also on all Server editions.