HowTo: Set an Environment Variable in Windows — Command Line and Registry
Environment variables are not often seen directly when using Windows. However there are cases, especially when using the command line, that setting and updating environment variables is a necessity. In this series we talk about the various approaches we can take to set them. In this article we look at how to interface with environment variables using the Command Prompt and Windows PowerShell. We also note where in the registry the environment variables are set, if you needed to access them in such a fashion.
Print environment variables
You can use environment variables in the values of other environment variables. It is then helpful to be able to see what environment variables are set already. This is how you do it:
Command Prompt
List all environment variables
Command Prompt — C:\>
Output
Print a particular environment variable:
Command Prompt — C:\>
Output
Windows PowerShell
List all environment variables
Windows PowerShell — PS C:\>
Output
Print a particular environment variable:
Windows PowerShell — PS C:\>
Output
Set Environment Variables
To set persistent environment variables at the command line, we will use setx.exe . It became part of Windows as of Vista/Windows Server 2008. Prior to that, it was part of the Windows Resource Kit. If you need the Windows Resource Kit, see Resources at the bottom of the page.
setx.exe does not set the environment variable in the current command prompt, but it will be available in subsequent command prompts.
User Variables
Command Prompt — C:\>
Open a new command prompt.
Command Prompt — C:\>
Output
System Variables
To edit the system variables, you’ll need an administrative command prompt. See HowTo: Open an Administrator Command Prompt in Windows to see how.
Command Prompt — C:\>
Registry
The location of the user variables in the registry is: HKEY_CURRENT_USER\ Environment . The location of the system variables in the registry is: HKEY_LOCAL_MACHINE\ SYSTEM\ CurrentControlSet\ Control\ Session Manager\ Environment .
When setting environment variables through the registry, they will not recognized immediately. One option is to log out and back in again. However, we can avoid logging out if we send a WM_SETTINGCHANGE message, which is just another line when doing this programatically, however if doing this on the command line it is not as straightforward.
One way is to get this message issued is to open the environment variables in the GUI, like we do in HowTo: Set an Environment Variable in Windows — GUI; we do not need to change anything, just open the Environment Variables window where we can see the environment variables, then hit OK .
Another way to get the message issued is to use setx , this allows everything to be done on the command line, however requires setting at least one environment variable with setx .
With Windows XP, the reg tool allows for accessing the registry from the command line. We can use this to look at the environment variables. This will work the same way in the command prompt or in powershell. This technique will also show the unexpanded environment variables, unlike the approaches shown for the command prompt and for powershell.
Recognized Environment Variables
When using the XML files MigDocs.xml, MigApp.xml, and MigUser.xml, you can use environment variables to identify folders that may be different on different computers. Constant special item ID list (CSIDL) values provide a way to identify folders that applications use frequently but may not have the same name or location on any given computer. For example, the documents folder may be C:\Users\ \My Documents on one computer and C:\Documents and Settings on another. You can use the asterisk (*) wildcard character in MigUser.xml, MigApp.xml and MigDoc.xml files. However, you cannot use the asterisk (*) wildcard characters in the Config.xml file.
In This Topic
Variables that are processed for the operating system and in the context of each user
You can use these variables within sections in the .xml files with context=UserAndSystem , context=User , and context=System .
Variable
Explanation
ALLUSERSAPPDATA
Same as CSIDL_COMMON_APPDATA.
ALLUSERSPROFILE
Refers to %PROFILESFOLDER%\Public or %PROFILESFOLDER%\all users.
COMMONPROGRAMFILES
Same as CSIDL_PROGRAM_FILES_COMMON.
COMMONPROGRAMFILES(X86)
Refers to the C:\Program Files (x86)\Common Files folder on 64-bit systems.
CSIDL_COMMON_ADMINTOOLS
VersionВ 10.0. The file-system directory that contains administrative tools for all users of the computer.
CSIDL_COMMON_ALTSTARTUP
The file-system directory that corresponds to the non-localized Startup program group for all users.
CSIDL_COMMON_APPDATA
The file-system directory that contains application data for all users. A typical path WindowsВ is C:\ProgramData.
CSIDL_COMMON_DESKTOPDIRECTORY
The file-system directory that contains files and folders that appear on the desktop for all users. A typical Windows® XP path is C:\Documents and Settings\All Users\Desktop. A typical path is C:\Users\Public\Desktop.
CSIDL_COMMON_DOCUMENTS
The file-system directory that contains documents that are common to all users. A typical path in WindowsВ XP is C:\Documents and Settings\All Users\Documents. A typical path is C:\Users\Public\Documents.
CSIDL_COMMON_FAVORITES
The file-system directory that serves as a common repository for favorites common to all users. A typical pathВ is C:\Users\Public\Favorites.
CSIDL_COMMON_MUSIC
The file-system directory that serves as a repository for music files common to all users. A typical pathВ is C:\Users\Public\Music.
CSIDL_COMMON_PICTURES
The file-system directory that serves as a repository for image files common to all users. A typical pathВ is C:\Users\Public\Pictures.
CSIDL_COMMON_PROGRAMS
The file-system directory that contains the directories for the common program groups that appear on the Start menu for all users. A typical pathВ is C:\ProgramData\Microsoft\Windows\Start Menu\Programs.
CSIDL_COMMON_STARTMENU
The file-system directory that contains the programs and folders which appear on the Start menu for all users. A typical path in Windows is C:\ProgramData\Microsoft\Windows\Start Menu.
CSIDL_COMMON_STARTUP
The file-system directory that contains the programs that appear in the Startup folder for all users. A typical path in WindowsВ XP is C:\Documents and Settings\All Users\Start Menu\Programs\Startup. A typical path is C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup.
CSIDL_COMMON_TEMPLATES
The file-system directory that contains the templates that are available to all users. A typical pathВ is C:\ProgramData\Microsoft\Windows\Templates.
CSIDL_COMMON_VIDEO
The file-system directory that serves as a repository for video files common to all users. A typical path is C:\Users\Public\Videos.
CSIDL_DEFAULT_APPDATA
Refers to the Appdata folder inside %DEFAULTUSERPROFILE%.
CSIDL_DEFAULT_LOCAL_APPDATA
Refers to the local Appdata folder inside %DEFAULTUSERPROFILE%.
CSIDL_DEFAULT_COOKIES
Refers to the Cookies folder inside %DEFAULTUSERPROFILE%.
CSIDL_DEFAULT_CONTACTS
Refers to the Contacts folder inside %DEFAULTUSERPROFILE%.
CSIDL_DEFAULT_DESKTOP
Refers to the Desktop folder inside %DEFAULTUSERPROFILE%.
CSIDL_DEFAULT_DOWNLOADS
Refers to the Downloads folder inside %DEFAULTUSERPROFILE%.
CSIDL_DEFAULT_FAVORITES
Refers to the Favorites folder inside %DEFAULTUSERPROFILE%.
CSIDL_DEFAULT_HISTORY
Refers to the History folder inside %DEFAULTUSERPROFILE%.
CSIDL_DEFAULT_INTERNET_CACHE
Refers to the Internet Cache folder inside %DEFAULTUSERPROFILE%.
CSIDL_DEFAULT_PERSONAL
Refers to the Personal folder inside %DEFAULTUSERPROFILE%.
CSIDL_DEFAULT_MYDOCUMENTS
Refers to the My Documents folder inside %DEFAULTUSERPROFILE%.
CSIDL_DEFAULT_MYPICTURES
Refers to the My Pictures folder inside %DEFAULTUSERPROFILE%.
CSIDL_DEFAULT_MYMUSIC
Refers to the My Music folder inside %DEFAULTUSERPROFILE%.
CSIDL_DEFAULT_MYVIDEO
Refers to the My Videos folder inside %DEFAULTUSERPROFILE%.
CSIDL_DEFAULT_RECENT
Refers to the Recent folder inside %DEFAULTUSERPROFILE%.
CSIDL_DEFAULT_SENDTO
Refers to the Send To folder inside %DEFAULTUSERPROFILE%.
CSIDL_DEFAULT_STARTMENU
Refers to the Start Menu folder inside %DEFAULTUSERPROFILE%.
CSIDL_DEFAULT_PROGRAMS
Refers to the Programs folder inside %DEFAULTUSERPROFILE%.
CSIDL_DEFAULT_STARTUP
Refers to the Startup folder inside %DEFAULTUSERPROFILE%.
CSIDL_DEFAULT_TEMPLATES
Refers to the Templates folder inside %DEFAULTUSERPROFILE%.
CSIDL_DEFAULT_QUICKLAUNCH
Refers to the Quick Launch folder inside %DEFAULTUSERPROFILE%.
CSIDL_FONTS
A virtual folder containing fonts. A typical path is C:\Windows\Fonts.
CSIDL_PROGRAM_FILESX86
The Program Files folder on 64-bit systems. A typical path is C:\Program Files(86).
CSIDL_PROGRAM_FILES_COMMONX86
A folder for components that are shared across applications on 64-bit systems. A typical path is C:\Program Files(86)\Common.
CSIDL_PROGRAM_FILES
The Program Files folder. A typical path is C:\Program Files.
CSIDL_PROGRAM_FILES_COMMON
A folder for components that are shared across applications. A typical path is C:\Program Files\Common.
CSIDL_RESOURCES
The file-system directory that contains resource data. A typical path is C:\Windows\Resources.
CSIDL_SYSTEM
The Windows System folder. A typical path is C:\Windows\System32.
CSIDL_WINDOWS
The Windows directory or system root. This corresponds to the %WINDIR% or %SYSTEMROOT% environment variables. A typical path is C:\Windows.
DEFAULTUSERPROFILE
Refers to the value in HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList [DefaultUserProfile].
PROFILESFOLDER
Refers to the value in HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList [ProfilesDirectory].
PROGRAMFILES
Same as CSIDL_PROGRAM_FILES.
PROGRAMFILES(X86)
Refers to the C:\Program Files (x86) folder on 64-bit systems.
SYSTEM
Refers to %WINDIR%\system32.
SYSTEM16
Refers to %WINDIR%\system.
SYSTEM32
Refers to %WINDIR%\system32.
SYSTEMPROFILE
Refers to the value in HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList\S-1-5-18 [ProfileImagePath].
SYSTEMROOT
Refers to the root of the system drive.
WINDIR
Refers to the Windows folder located on the system drive.
Variables that are recognized only in the user context
You can use these variables in the .xml files within sections with context=User and context=UserAndSystem .
Variable
Explanation
APPDATA
Same as CSIDL_APPDATA.
CSIDL_ADMINTOOLS
The file-system directory that is used to store administrative tools for an individual user. The MicrosoftВ® Management Console (MMC) saves customized consoles to this directory, which roams with the user profile.
CSIDL_ALTSTARTUP
The file-system directory that corresponds to the user’s non-localized Startup program group.
CSIDL_APPDATA
The file-system directory that serves as a common repository for application-specific data. A typical path is C:\Documents and Settings\username\Application Data or C:\Users\username\AppData\Roaming.
CSIDL_BITBUCKET
The virtual folder that contains the objects in the user’s Recycle Bin.
CSIDL_CDBURN_AREA
The file-system directory acting as a staging area for files waiting to be written to CD. A typical path is C:\Users\username\AppData\Local\Microsoft\Windows\MasteredBurning\Disc Burning.
CSIDL_CONNECTIONS
The virtual folder representing Network Connections that contains network and dial-up connections.
CSIDL_CONTACTS
This refers to the Contacts folder in %CSIDL_PROFILE%.
CSIDL_CONTROLS
The virtual folder that contains icons for the Control Panel items.
CSIDL_COOKIES
The file-system directory that serves as a common repository for Internet cookies. A typical path is C:\Users\username\AppData\Roaming\Microsoft\Windows\Cookies.
CSIDL_DESKTOP
The virtual folder representing the Windows desktop.
CSIDL_DESKTOPDIRECTORY
The file-system directory used to physically store file objects on the desktop, which should not be confused with the desktop folder itself. A typical path is C:\Users\username\Desktop.
CSIDL_DRIVES
The virtual folder representing My Computer that contains everything on the local computer: storage devices, printers, and Control Panel. The folder may also contain mapped network drives.
CSIDL_FAVORITES
The file-system directory that serves as a common repository for the user’s favorites. A typical path is C:\Users\Username\Favorites.
CSIDL_HISTORY
The file-system directory that serves as a common repository for Internet history items.
CSIDL_INTERNET
A virtual folder for Internet Explorer.
CSIDL_INTERNET_CACHE
The file-system directory that serves as a common repository for temporary Internet files. A typical path is C:\Users\username\AppData\Local\Microsoft\Windows\Temporary Internet Files
CSIDL_LOCAL_APPDATA
The file-system directory that serves as a data repository for local, non-roaming applications. A typical path is C:\Users\username\AppData\Local.
CSIDL_MYDOCUMENTS
The virtual folder representing My Documents.A typical path is C:\Users\Username\Documents.
CSIDL_MYMUSIC
The file-system directory that serves as a common repository for music files. A typical path is C:\Users\Username\Music.
CSIDL_MYPICTURES
The file-system directory that serves as a common repository for image files. A typical path is C:\Users\Username\Pictures.
CSIDL_MYVIDEO
The file-system directory that serves as a common repository for video files. A typical path is C:\Users\Username\Videos.
CSIDL_NETHOOD
A file-system directory that contains the link objects that may exist in the My Network Places virtual folder. It is not the same as CSIDL_NETWORK, which represents the network namespace root. A typical path is C:\Users\Username\AppData\Roaming\Microsoft\Windows\Network Shortcuts.
CSIDL_NETWORK
A virtual folder representing My Network Places, the root of the network namespace hierarchy.
CSIDL_PERSONAL
The virtual folder representing the My Documents desktop item. This is equivalent to CSIDL_MYDOCUMENTS.
A typical path is C:\Documents and Settings\username\My Documents.
CSIDL_PLAYLISTS
The virtual folder used to store play albums, typically C:\Users\username\My Music\Playlists.
CSIDL_PRINTERS
The virtual folder that contains installed printers.
CSIDL_PRINTHOOD
The file-system directory that contains the link objects that can exist in the Printers virtual folder. A typical path is C:\Users\username\AppData\Roaming\Microsoft\Windows\Printer Shortcuts.
CSIDL_PROFILE
The user’s profile folder. A typical path is C:\Users\Username.
CSIDL_PROGRAMS
The file-system directory that contains the user’s program groups, which are themselves file-system directories. A typical path is C:\Users\Username\AppData\Roaming\Microsoft\Windows\Start Menu\Programs.
CSIDL_RECENT
The file-system directory that contains shortcuts to the user’s most recently used documents. A typical path is C:\Users\Username\AppData\Roaming\Microsoft\Windows\Recent.
CSIDL_SENDTO
The file-system directory that contains Send To menu items. A typical path is C:\Users\username\AppData\Roaming\Microsoft\Windows\SendTo.
CSIDL_STARTMENU
The file-system directory that contains Start menu items. A typical path in WindowsВ XP is C:\Documents and Settings\username\Start Menu. A typical path in WindowsВ Vista, WindowsВ 7, or WindowsВ 8 is C:\Users\Username\AppData\Roaming\Microsoft\Windows\Start Menu.
CSIDL_STARTUP
The file-system directory that corresponds to the user’s Startup program group. A typical path is C:\Users\Username\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup.
CSIDL_TEMPLATES
The file-system directory that serves as a common repository for document templates. A typical path is C:\Users\username\AppData\Roaming\Microsoft\Windows\Templates.
HOMEPATH
Same as the standard environment variable.
TEMP
The temporary folder on the computer. A typical path is %USERPROFILE%\AppData\Local\Temp.
TMP
The temporary folder on the computer. A typical path is %USERPROFILE%\AppData\Local\Temp.
USERPROFILE
Same as CSIDL_PROFILE.
USERSID
Represents the current user-account security identifier (SID). For example,
