Windows Environment Variables

Windows environment variables are dynamic values that affect process behavior. This page provides a quick reference for the most commonly used variables.

Common Environment Variables

Variable	Description	Example Path
`%APPDATA%`	Current user's Application Data folder	`C:\Users\Username\AppData\Roaming`
`%TEMP%`	Temporary folder for current user	`C:\Users\Username\AppData\Local\Temp`
`%USERPROFILE%`	Current user's profile folder	`C:\Users\Username`
`%PROGRAMFILES%`	Program Files folder	`C:\Program Files`
`%SYSTEMROOT%`	Windows installation directory	`C:\Windows`
`%USERNAME%`	Current user's username	`Username`
`%WINDIR%`	Windows directory	`C:\Windows`
`%HOMEPATH%`	Current user's home folder	`\Users\Username`
`%LOCALAPPDATA%`	Current user's local AppData folder	`C:\Users\Username\AppData\Local`

Special Shell Locations

Command	Location
`shell:startup`	User's Startup folder
`shell:common startup`	All Users Startup folder
`shell:appdata`	Application Data folder
`shell:local appdata`	Local Application Data folder
`shell:programs`	Start Menu Programs folder
`shell:desktop`	Desktop folder
`shell:downloads`	Downloads folder
`shell:fonts`	Fonts folder

Full paths:

shell:startup: C:\Users\Username\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup
shell:common startup: C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup

How to Access

Using Windows Run Dialog

Press Win + R
Type the variable or shell command
Press Enter

Examples:

%APPDATA%
%TEMP%
shell:startup

Using File Explorer

Type the variable in the address bar:

%USERPROFILE%
%PROGRAMFILES%

Using Command Prompt

cmd

:: View variable value
echo %APPDATA%

:: Open folder
explorer %TEMP%

:: List all environment variables
set

Using PowerShell

powershell

# View variable value
$env:APPDATA

# Open folder
explorer $env:TEMP

# List all environment variables
dir env:
Get-ChildItem env:

System Variables

Variable	Description	Example Value
`%ALLUSERSPROFILE%`	All Users Profile	`C:\ProgramData`
`%COMMONPROGRAMFILES%`	Common Program Files	`C:\Program Files\Common Files`
`%COMSPEC%`	Command Processor	`C:\Windows\System32\cmd.exe`
`%HOMEDRIVE%`	User's home drive	`C:`
`%LOGONSERVER%`	Domain controller	`\\DC01`
`%PATH%`	Executable search path	`C:\Windows\System32;...`
`%PATHEXT%`	Executable file extensions	`.COM;.EXE;.BAT;...`
`%PROCESSOR_ARCHITECTURE%`	Processor architecture	`AMD64` or `x86`
`%PUBLIC%`	Public user profile	`C:\Users\Public`
`%SYSTEMDRIVE%`	System drive	`C:`

Program Files Variables

Variable	Description	64-bit System	32-bit System
`%PROGRAMFILES%`	Program Files folder	`C:\Program Files`	`C:\Program Files`
`%PROGRAMFILES(X86)%`	32-bit programs on 64-bit	`C:\Program Files (x86)`	N/A
`%PROGRAMW6432%`	64-bit programs	`C:\Program Files`	N/A

AppData Folders

Windows applications store user-specific data in three AppData subfolders:

Variable	Folder	Purpose	Example
`%APPDATA%`	Roaming	Synced across domain	Settings, profiles
`%LOCALAPPDATA%`	Local	Machine-specific	Caches, temp data
N/A	LocalLow	Low-integrity apps	Browser data

Full paths:

%APPDATA%: C:\Users\Username\AppData\Roaming
%LOCALAPPDATA%: C:\Users\Username\AppData\Local
LocalLow: C:\Users\Username\AppData\LocalLow

Temp Folders

Variable	Scope	Path
`%TEMP%`	Current user	`C:\Users\Username\AppData\Local\Temp`
`%TMP%`	Current user (same as TEMP)	`C:\Users\Username\AppData\Local\Temp`
N/A	System-wide	`C:\Windows\Temp`

Setting Environment Variables

Using GUI

Press Win + R, type sysdm.cpl, press Enter
Click "Advanced" tab
Click "Environment Variables" button
Add or edit variables

Using Command Prompt

cmd

:: Set for current session only
set MY_VAR=value

:: Set permanently (user)
setx MY_VAR "value"

:: Set permanently (system) - requires admin
setx MY_VAR "value" /M

:: Add to PATH
setx PATH "%PATH%;C:\new\path"

Using PowerShell

powershell

# Set for current session only
$env:MY_VAR = "value"

# Set permanently (user)
[Environment]::SetEnvironmentVariable("MY_VAR", "value", "User")

# Set permanently (system) - requires admin
[Environment]::SetEnvironmentVariable("MY_VAR", "value", "Machine")

# Add to PATH (user)
$path = [Environment]::GetEnvironmentVariable("PATH", "User")
[Environment]::SetEnvironmentVariable("PATH", "$path;C:\new\path", "User")

PATH Variable

The PATH variable contains directories where Windows searches for executables.

View PATH

Command Prompt:

cmd

echo %PATH%

PowerShell:

powershell

$env:PATH
$env:PATH -split ';'  # Display as list

Add to PATH

Temporary (current session):

cmd

:: Command Prompt
set PATH=%PATH%;C:\new\path

powershell

# PowerShell
$env:PATH += ";C:\new\path"

Permanent:

powershell

# PowerShell (user PATH)
$path = [Environment]::GetEnvironmentVariable("PATH", "User")
$newPath = "$path;C:\new\path"
[Environment]::SetEnvironmentVariable("PATH", $newPath, "User")

Common Use Cases

Clear Temp Files

cmd

:: Delete temp files
del /q /f /s %TEMP%\*

powershell

# PowerShell
Remove-Item -Path "$env:TEMP\*" -Recurse -Force -ErrorAction SilentlyContinue

Open Common Locations

cmd

:: Open Windows directory
explorer %WINDIR%

:: Open user profile
explorer %USERPROFILE%

:: Open Program Files
explorer %PROGRAMFILES%

:: Open Startup folder
explorer shell:startup

Find Application Data

cmd

:: Find app settings
explorer %APPDATA%\ApplicationName

:: Find local cache
explorer %LOCALAPPDATA%\ApplicationName

Development Variables

Java

cmd

echo %JAVA_HOME%
echo %JRE_HOME%

Node.js

cmd

echo %NODE_PATH%

Python

cmd

echo %PYTHONPATH%

.NET

cmd

echo %DOTNET_ROOT%

Troubleshooting

Variable Not Found

Check spelling and case
Ensure variable is set (use set or dir env:)
Restart terminal after setting permanent variables
Check variable scope (user vs system)

PATH Too Long

Windows has a 260-character limit for paths (in some contexts):

Use shorter folder names
Move programs closer to drive root

Enable long path support (Windows 10 1607+):

Registry: HKLM\SYSTEM\CurrentControlSet\Control\FileSystem
Key: LongPathsEnabled = 1

Changes Not Taking Effect

After modifying environment variables:

Close and reopen terminal windows
Log out and log back in
Restart Windows (for system-wide changes)

Windows Environment Variables

Common Environment Variables

Special Shell Locations

How to Access

Using Windows Run Dialog

Using File Explorer

Using Command Prompt

Using PowerShell

System Variables

Program Files Variables

AppData Folders

Temp Folders

Setting Environment Variables

Using GUI

Using Command Prompt

Using PowerShell

PATH Variable

View PATH

Add to PATH

Common Use Cases

Clear Temp Files

Open Common Locations

Find Application Data

Development Variables

Java

Node.js

Python

.NET

Troubleshooting

Variable Not Found

PATH Too Long

Changes Not Taking Effect

See Also

External Resources

Windows Environment Variables ​

Common Environment Variables ​

Special Shell Locations ​

How to Access ​

Using Windows Run Dialog ​

Using File Explorer ​

Using Command Prompt ​

Using PowerShell ​

System Variables ​

Program Files Variables ​

AppData Folders ​

Temp Folders ​

Setting Environment Variables ​

Using GUI ​

Using Command Prompt ​

Using PowerShell ​

PATH Variable ​

View PATH ​

Add to PATH ​

Common Use Cases ​

Clear Temp Files ​

Open Common Locations ​

Find Application Data ​

Development Variables ​

Java ​

Node.js ​

Python ​

.NET ​

Troubleshooting ​

Variable Not Found ​

PATH Too Long ​

Changes Not Taking Effect ​

See Also ​

External Resources ​

Windows Environment Variables

Common Environment Variables

Special Shell Locations

How to Access

Using Windows Run Dialog

Using File Explorer

Using Command Prompt

Using PowerShell

System Variables

Program Files Variables

AppData Folders

Temp Folders

Setting Environment Variables

Using GUI

Using Command Prompt

Using PowerShell

PATH Variable

View PATH

Add to PATH

Common Use Cases

Clear Temp Files

Open Common Locations

Find Application Data

Development Variables

Java

Node.js

Python

.NET

Troubleshooting

Variable Not Found

PATH Too Long

Changes Not Taking Effect

See Also

External Resources