Windows XP includes powerful commandline admin utilities including reg which allows powerful scripting of the registry.

reg /?

Console Registry Tool for Windows - version 3.0
Copyright (C) Microsoft Corp. 1981-2001.  All rights reserved


REG Operation [Parameter List]

  Operation  [ QUERY   | ADD    | DELETE  | COPY    |
               SAVE    | LOAD   | UNLOAD  | RESTORE |
               COMPARE | EXPORT | IMPORT ]

Return Code: (Except of REG COMPARE)

  0 - Succussful
  1 - Failed

For help on a specific operation type:

  REG Operation /?

Examples:

  REG QUERY /?
  REG ADD /?
  REG DELETE /?
  REG COPY /?
  REG SAVE /?
  REG RESTORE /?
  REG LOAD /?
  REG UNLOAD /?
  REG COMPARE /?
  REG EXPORT /?
  REG IMPORT /?


reg query /?

Console Registry Tool for Windows - version 3.0
Copyright (C) Microsoft Corp. 1981-2001.  All rights reserved


REG QUERY KeyName [/v ValueName | /ve] [/s]

  KeyName    [\Machine\]FullKey
    Machine - Name of remote machine,  omitting defaults to the current machine
         Only HKLM and HKU are available on remote machines
    FullKey  - in the form of ROOTKEY\SubKey name
         ROOTKEY  [ HKLM | HKCU | HKCR | HKU | HKCC ]
         SubKey  - The full name of a registry key under the selected ROOTKEY
  /v  query for a specific registry key
         ValueName  - The name, under the selected Key, to query
         if omitted, all values under the Key are queried
  /ve query for the default value or empty value name 
  /s  queries all subkeys and values

Examples:

  REG QUERY HKLM\Software\Microsoft\ResKit /v Version
    Displays the value of the registry value Version

  REG QUERY HKLM\Software\Microsoft\ResKit\Nt\Setup /s
    Displays all subkeys and values under the registry key Setup


reg add /?

Console Registry Tool for Windows - version 3.0
Copyright (C) Microsoft Corp. 1981-2001.  All rights reserved


REG ADD KeyName [/v ValueName | /ve] [/t Type] [/s Separator] [/d Data] [/f]

  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

  /v       The value name, under the selected Key, to add

  /ve      adds an empty value name  for the key

  /t       RegKey data types
           [ REG_SZ    | REG_MULTI_SZ  | REG_DWORD_BIG_ENDIAN    |
             REG_DWORD | REG_BINARY    | REG_DWORD_LITTLE_ENDIAN |
             REG_NONE  | REG_EXPAND_SZ ]
           If omitted, REG_SZ is assumed

  /s       Specify one charactor that you use as the separator in your data
           string for REG_MULTI_SZ. If omitted, use "\0" as the separator

  /d       The data to assign to the registry ValueName being added

  /f       Force overwriting the existing registry entry without prompt

Examples:

  REG ADD \\ABC\HKLM\Software\MyCo
    Adds a key HKLM\Software\MyCo on remote machine ABC

  REG ADD HKLM\Software\MyCo /v Data /t REG_BINARY /d fe340ead
    Adds a value (name: Data, type: REG_BINARY, data: fe340ead)

  REG ADD HKLM\Software\MyCo /v MRU /t REG_MULTI_SZ /d fax\0mail
    Adds a value (name: MRU, type: REG_MUTLI_SZ, data: fax\0mail\0\0)

  REG ADD HKLM\Software\MyCo /v Path /t REG_EXPAND_SZ /d %%systemroot%%
    Adds a value (name: Path, type: REG_EXPAND_SZ, data: %systemroot%)
    Notice:  Use the double percentage ( %% ) inside the expand string



reg delete /?

Console Registry Tool for Windows - version 3.0
Copyright (C) Microsoft Corp. 1981-2001.  All rights reserved


REG DELETE KeyName [/v ValueName | /ve | /va] [/f]

  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 
  /va        delete all values under this key
  /f         Forces the deletion without propmt

Examples:

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

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


reg copy /?

Console Registry Tool for Windows - version 3.0
Copyright (C) Microsoft Corp. 1981-2001.  All rights reserved


REG COPY KeyName1 KeyName2 [/s] [/f]

  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
  /s         Copies all subkeys and values
  /f         Forces the copy without propmt

Examples:

  REG COPY HKLM\Software\MyCo\MyApp HKLM\Software\MyCo\SaveMyApp /s
    Copies all subkeys and values under the key MyApp to the key SaveMyApp

  REG COPY \\ZODIAC\HKLM\Software\MyCo HKLM\Software\MyCo1
    Copies all values under the key MyCo on ZODIAC to the key MyCo1
    on the current machine


reg save /?

Console Registry Tool for Windows - version 3.0
Copyright (C) Microsoft Corp. 1981-2001.  All rights reserved


REG SAVE KeyName FileName

  KeyName    ROOTKEY\SubKey
    ROOTKEY  [ HKLM | HKCU | HKCR | HKU | HKCC ]
    SubKey   The full name of a registry key under the selected ROOTKEY
  FileName   The name of the disk file to save. If no path is specified, the
             file is created in the current folder of the calling process

Examples:

  REG SAVE HKLM\Software\MyCo\MyApp AppBkUp.hiv
    Saves the hive MyApp to the file AppBkUp.hiv in the current folder


reg restore /?

Console Registry Tool for Windows - version 3.0
Copyright (C) Microsoft Corp. 1981-2001.  All rights reserved


REG RESTORE KeyName FileName

  KeyName    ROOTKEY\SubKey (local machine only)
    ROOTKEY  [ HKLM | HKCU | HKCR | HKU | HKCC ]
    SubKey   The full name of a registry key to restore the hive file into.
             Overwriting the existing key's values and subkeys
  FileName   The name of the hive file to restore
             You must use REG SAVE to create this file

Examples:

  REG RESTORE HKLM\Software\Microsoft\ResKit NTRKBkUp.hiv
    Restores the file NTRKBkUp.hiv overwriting the key ResKit


reg load /?

Console Registry Tool for Windows - version 3.0
Copyright (C) Microsoft Corp. 1981-2001.  All rights reserved


REG LOAD KeyName FileName

  KeyName    ROOTKEY\SubKey (local machine only)
    ROOTKEY  [ HKLM | HKU ]
    SubKey   The key name to load the hive file into. Creating a new key
  FileName   The name of the hive file to load
             You must use REG SAVE to create this file

Examples:

  REG LOAD HKLM\TempHive TempHive.hiv
    Loads the file TempHive.hiv to the Key HKLM\TempHive


reg unload /?

Console Registry Tool for Windows - version 3.0
Copyright (C) Microsoft Corp. 1981-2001.  All rights reserved


REG UNLOAD KeyName

  KeyName    ROOTKEY\SubKey (local machine only)
    ROOTKEY  [ HKLM | HKU ]
    SubKey   The key name of the hive to unload

Examples:

  REG UNLOAD HKLM\TempHive
    Unloads the hive TempHive in HKLM


reg compare /?

Console Registry Tool for Windows - version 3.0
Copyright (C) Microsoft Corp. 1981-2001.  All rights reserved


REG COMPARE KeyName1 KeyName2 [/v ValueName | /ve] [Output] [/s]

  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
             If FullKey2 is not specified, FullKey2 is the same as FullKey1
    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 compare
             When omitted, all values under the Key are compared
  /ve        compare the value of empty value name 
  /s         Compare all subkeys and values
  Output     [/oa | /od | /os | /on]
             When omitted, output only differences
    /oa      Output all of differences and matches
    /od      Output only differences
    /os      Output only matches
    /on      No output

Return Code:

  0 - Succussful, the result compared is identical
  1 - Failed
  2 - Successful, the result compared is different

Examples:

  REG COMPARE HKLM\Software\MyCo\MyApp HKLM\Software\MyCo\SaveMyApp
    Compares all values under the key MyApp with SaveMyApp

  REG COMPARE HKLM\Software\MyCo HKLM\Software\MyCo1 /v Version
    Compares the value Version under the key MyCo and MyCo1

  REG COMPARE \\ZODIAC\HKLM\Software\MyCo \\. /s
    Compares all subkeys and values under HKLM\Software\MyCo on ZODIAC
    with the same key on the current machine


reg export /?

Console Registry Tool for Windows - version 3.0
Copyright (C) Microsoft Corp. 1981-2001.  All rights reserved


REG EXPORT KeyName FileName

  Keyname    ROOTKEY\SubKey (local machine only)
    ROOTKEY  [ HKLM | HKCU | HKCR | HKU | HKCC ]
    SubKey   The full name of a registry key under the selected ROOTKEY
  FileName   The name of the disk file to export

Examples:

  REG EXPORT HKLM\Software\MyCo\MyApp AppBkUp.reg
    Exports all subkeys and values of the key MyApp to the file AppBkUp.reg


reg import /?

Console Registry Tool for Windows - version 3.0
Copyright (C) Microsoft Corp. 1981-2001.  All rights reserved


REG IMPORT FileName

  FileName  The name of the disk file to import (local machine only)

Examples:

  REG IMPORT AppBkUp.reg
    Imports registry entrys from the file AppBkUp.reg