C:\>reg delete /?

REG DELETE KeyName [/v ValueName | /ve | /va] [/f] [/reg:32 | /reg:64]

  KeyName    [\\Machine\]FullKey
    Machine  Name of remote machine - omitting defaults to the current machine.
             Only HKLM and HKU are available on remote machines.
    FullKey  ROOTKEY\SubKey
    ROOTKEY  [ HKLM | HKCU | HKCR | HKU | HKCC ]
    SubKey   The full name of a registry key under the selected ROOTKEY.

  ValueName  The value name, under the selected Key, to delete.
             When omitted, all subkeys and values under the Key are deleted.

  /ve        delete the value of empty value name (Default).

  /va        delete all values under this key.

  /f         Forces the deletion without prompt.

  /reg:32    Specifies the key should be accessed using the 32-bit registry
             view.

  /reg:64    Specifies the key should be accessed using the 64-bit registry
             view.

Examples:

  REG DELETE HKLM\Software\MyCo\MyApp\Timeout
    Deletes the registry key Timeout and all its subkeys and values

  REG DELETE \\ZODIAC\HKLM\Software\MyCo /v MTU
    Deletes the registry value MTU under MyCo on ZODIAC

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