The FDISK command

Use the undocumented switch /newmbr to force <FDISK to write a new master 
boot record to the harddisk. This is equal to the switch /mbr of the DOS 
FDISK command. The switch is documented in the Online Reference of WARP 4. 

If FDISK refuses to do something you want it to do (e.g. create or delete 
a partition), use FDISK in non-interactive mode with parameters. In most 
cases this helps. 

Please be aware that when FDISK is run in non-interactive mode the 
position (i.e., order) of parameters given on the command line is 
significant. 

Note:  Do not rely on the return code of <FDISK.