FDISK.EXE is a DOS based command line driven Microsoft partitioning utility. Its purpose is to display boot, disk and partition information, modify existing partitions, create new ones and/or delete the ones you want on all installed fixed hard disk(s), but ONLY WITH COMPLETE DATA LOSS! so always back up your hard 
disk before running to avoid having to rely on data recovery services!"
run one of these commands from any DOS prompt:
FDISK /?
or:
HELP FDISK
to display the FDISK.EXE help screen.

HIDDEN PARAMETERS
Hidden parameter are not documented by Microsoft and is find by users threw experiments.

1) FDISK /FPRMT :
FDISK /FPRMT bypasses the FDISK startup screen, but enables interactive FAT16/FAT32 support. This can be used to force FDISK to create FAT32 partitions smaller than 512 MB, normally not possible by default.
2) FDISK /MBR :
FDISK /MBR recreates the boot sector of the first (bootable) hard disk overwriting it with a fresh copy, by writing a new Master Boot Record (MBR) based on existent disk structure, without altering the partition table information.
Can be used to repair a damaged/corrupted MBR (i.e. by a virus).

3) FDISK /ACTOK :
FDISK /ACTOK skips disk integrity checking, thus speeding up the partitioning process.
4) FDISK /PARTN :
FDISK /PARTN saves the partition information to a plain text file called PARTSAV.FIL, which can be viewed afterwards using any text editor/viewer, like EDIT.COM in DOS or Notepad in Windows.

Formatting Partitions

FORMAT.COM is an external MS-DOS command, located by default in C:\Windows\Command
Hidden Parameter :
Hidden parameter are not documented by Microsoft and is find by users threw experiments.

1) FORMAT /AUTOTEST :
FORMAT /AUTOTEST checks for the existing format of your disk, unless the /U (UNCONDITIONAL) parameter is also used, and then proceeds with an UNATTENDED DISK(ETTE) FORMAT:

DOES NOT prompt for a volume label!
DOES NOT prompt to format another disk(ette)!
NO delay: NO user intervention!
Ends WITHOUT pausing!
After completion, it DOES display disk space statistics.

2)FORMAT drive: /U :
FORMAT drive: /U performs an UNCONDITIONAL format, which DESTROYS every byte of data on ANY hard disk/floppy by overwriting it with zeroes (hex F6h).

3) FORMAT drive: /SELECT /U :
FORMAT drive: /SELECT /U makes a disk(ette) UNREADABLE by filling the system area (sector 0) with zeroes (hex F6h), due to using these two incompatible options together. All other sectors are left intact.

95/98/NT SETUP SWITCHES

If you try to install Windows 95/98 from a DOS prompt, SETUP allows several command line switches, also available to their Windows GUI based counterpart.

Note that most switches are NOT case sensitive.

Run SETUP /?:
it will show the available parameters.

UNDOCUMENTED SETUP SWITCHES:

/IP Bypasses detection of undocumented plug and play devices.

/IR Bypasses detection of system CMOS/BIOS and does not update Master Boot Record (MBR).It is very helpful in installing windows on the system on which LINUX is already installed

/IW Bypasses Microsoft EULA licensing screens/dialog boxes.

/NTLDR Bypasses existing Operating System detection.

WIN.COM HIDDEN PARAMETERS

WIN.COM is the Windows GUI (Graphical User Interface) command line executable,
located in C:\Windows (default)
Hidden Parameter :
Hidden parameter are not documented by Microsoft and is find by users threw experiments.

1.) win/W [Windows 95 and above ONLY]

win/W generates this message:

"Press any key to continue...
Pressing a key reboots the system back to Windows 95 (98)."

waiting for user input (key press), and then restarts the computer (warm reboot), restoring the original CONFIG.SYS and AUTOEXEC.BAT files in the root directory of the boot drive from CONFIG.WOS and AUTOEXEC.WOS (if any).

This is useful when the computer is restarted after interrupting a "single" mode MS-DOS session, because of this CONFIG.SYS line:
DOS=SINGLE
which does NOT allow Windows 95/98 GUI to load. This switch works ONLY if executed from the native/real/true MS-DOS mode OUTSIDE the Windows 95/98 GUI, NOT from WITHIN Windows in a DOS box/session.

2.)win/Z [Windows 95B OSR 2.1 and above ONLY]

win/Z automatically forces the ATX power supply to (soft-)power off the
computer ONLY on ATX motherboards, without prompting or waiting for input (key
press).
This switch works ONLY if executed from the native/real/true MS-DOS mode
OUTSIDE the Windows GUI, NOT from WITHIN Windows in a DOS prompt/box/session.

---

---