How to export and import environment variables in windows?

Question

You can use RegEdit to export the following two keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment

HKEY_CURRENT_USER\Environment

The first set are system/global environment variables; the second set are user-level variables. Edit as needed and then import the .reg files on the new machine.

I would use the SET command from the command prompt to export all the variables, rather than just PATH as recommended above.

C:\> SET >> allvariables.txt

To import the variablies, one can use a simple loop:

C:\> for /F %A in (allvariables.txt) do SET %A

To export user variables, open a command prompt and use regedit with /e

Example :

regedit /e "%userprofile%\Desktop\my_user_env_variables.reg" "HKEY_CURRENT_USER\Environment"

Combine @vincsilver and @jdigital's answers with some modifications,

1. export .reg to current directory
2. add date mark

code:

set TODAY=%DATE:~0,4%-%DATE:~5,2%-%DATE:~8,2%

regedit /e "%CD%\user_env_variables[%TODAY%].reg" "HKEY_CURRENT_USER\Environment"
regedit /e "%CD%\global_env_variables[%TODAY%].reg" "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment"

Output would like:

global_env_variables[2017-02-14].reg
user_env_variables[2017-02-14].reg

You can get access to the environment variables in either the command line or in the registry.

Command Line

If you want a specific environment variable, then just type the name of it (e.g. PATH), followed by a >, and the filename to write to. The following will dump the PATH environment variable to a file named path.txt.

C:\> PATH > path.txt

Registry Method

The Windows Registry holds all the environment variables, in different places depending on which set you are after. You can use the registry Import/Export commands to shift them into the other PC.

For System Variables:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment

For User Variables:

HKEY_CURRENT_USER\Environment

Here is my PowerShell method

gci env:* | sort-object name | Where-Object {$_.Name -like "MyApp*"} | Foreach {"[System.Environment]::SetEnvironmentVariable('$($_.Name)', '$($_.Value)', 'Machine')"}

What it does

1. Scoops up all environment variables
2. Filters them
3. Emits the formatted PowerShell needed to recreate them on another machine (assumes all are set at machine level)

So after running this on the source machine, simply transfer output onto the target machine and execute (elevated prompt if setting at machine level)

My favorite method for doing this is to write it out as a batch script to combine both user variables and system variables into a single backup file like so, create an environment-backup.bat file and put in it:

@echo off
:: RegEdit can only export into a single file at a time, so create two temporary files.
regedit /e "%CD%\environment-backup1.reg" "HKEY_CURRENT_USER\Environment"
regedit /e "%CD%\environment-backup2.reg" "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment"

:: Concatenate into a single file and remove temporary files.
type "%CD%\environment-backup1.reg" "%CD%\environment-backup2.reg" > environment-backup.reg
del "%CD%\environment-backup1.reg"
del "%CD%\environment-backup2.reg"

This creates environment-backup.reg which you can use to re-import existing environment variables. This will add & override new variables, but not delete existing ones :)