Windows – Setting a system environment variable from a Windows batch file

batch-filecmdenvironment-variableswindows

Is it possible to set a environment variable at the system level from a command prompt in Windows 7 (or even XP for that matter). I am running from an elevated command prompt.

When I use the set command (set name=value), the environment variable seems to be only valid for the session of the command prompt.

Best Answer

The XP Support Tools (which can be installed from your XP CD) come with a program called setx.exe:

C:\Program Files\Support Tools>setx /?

SETX: This program is used to set values in the environment
of the machine or currently logged on user using one of three modes.

1) Command Line Mode: setx variable value [-m]
   Optional Switches:
    -m  Set value in the Machine environment. Default is User.

...
For more information and example use: SETX -i

I think Windows 7 actually comes with setx as part of a standard install.

Related Solutions

How to pass arguments to a batch file

Another useful tip is to use %* to mean "all". For example:

echo off
set arg1=%1
set arg2=%2
shift
shift
fake-command /u %arg1% /p %arg2% %*

When you run:

test-command admin password foo bar

the above batch file will run:

fake-command /u admin /p password admin password foo bar

I may have the syntax slightly wrong, but this is the general idea.

Windows – Batch file to delete files older than N days

Enjoy:

forfiles -p "C:\what\ever" -s -m *.* -d <number of days> -c "cmd /c del @path"

See forfiles documentation for more details.

For more goodies, refer to An A-Z Index of the Windows XP command line.

If you don't have forfiles installed on your machine, copy it from any Windows Server 2003 to your Windows XP machine at %WinDir%\system32\. This is possible since the EXE is fully compatible between Windows Server 2003 and Windows XP.

Later versions of Windows and Windows Server have it installed by default.

For Windows 7 and newer (including Windows 10):

The syntax has changed a little. Therefore the updated command is:

forfiles /p "C:\what\ever" /s /m *.* /D -<number of days> /C "cmd /c del @path"

Best Answer

Related Solutions

How to pass arguments to a batch file

Windows – Batch file to delete files older than N days

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