How to persistently set a variable in Windows 7 from a batch file?

I am trying to set the PATH environment variable in windows 7 using a bat-file; however it does not seem to work.

I am using this windows command:

set PATH=%cd%;%path%
pause

However it only appears to be valid for this cmd instance. I want it to be permanent, since I first set the PATH and then run a program which needs to locate the libraries in that folder.

Solution 1:

Use setx.exe instead of set.

setx PATH "%cd%;%path%;"
pause

Note that this sets the path for all future cmd instances, but not for the current one. If you need that, also run your original set command.

UPDATE: The second parameter needs to be quoted if it contains spaces (which %path% always has). Be warned that if the last character in your %path% is a backslash, it will escape the trailing quote and the last path entry will stop working. I get around that by appending a semicolon before the closing quote.

If you don't want to risk getting ";;;;;;" at the end of your path after repeated runs, then instead strip any trailing backslash from the %path% variable before setting, and it will work correctly.

Solution 2:

If you want to do it in a batch file, use the reg command to change the path value in the registry at the HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment key.

Something like:

reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /v Path /t REG_SZ /d "%path%;c:\newpath"

Check that the path in the %path% variable matches the system path.