Drastically rewrote the path script to handle Explorer's stubborn grasp of EnvVars. Tested on Win7.

1-setup-path-win.bat

@@ -1,14 +1,71 @@
-@echo off
+@SETLOCAL ENABLEEXTENSIONS ENABLEDELAYEDEXPANSION
+@ECHO OFF
+SET CMDLINERUNSTR=%SystemRoot%\system32\cmd.exe
 
-reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /f /v Path /t REG_SZ /d "%path%;C:\MinGW\bin;C:\MinGW\msys\1.0\bin" > nul
-echo.
+SET NEWPATH1="C:\MinGW\msys\1.0\bin"
+SET NEWPATH2="C:\MinGW\bin"
 
-if NOT ["%errorlevel%"]==["0"] (
-	echo FAILED. You probably just need to run the script with administrator privileges.
-) else (
-	echo Success!
-	setx QMK QMK > nul
-)
+:: Make sure paths exist
+IF NOT EXIST !NEWPATH1! (ECHO Path not found: %NEWPATH1% && GOTO ExitBatch)
+IF NOT EXIST !NEWPATH2! (ECHO Path not found: %NEWPATH2% && GOTO ExitBatch)
 
-echo.
-pause
+:: Add paths
+CALL :AddPath %NEWPATH1%
+CALL :AddPath %NEWPATH2%
+
+:: Branch to UpdateEnv if we need to update
+IF DEFINED UPDATE (GOTO UpdateEnv)
+
+GOTO ExitBatch
+
+:: -----------------------------------------------------------------------------
+
+:UpdateEnv
+ECHO Making updated PATH go live . . .
+REG delete HKCU\Environment /F /V TEMPVAR > nul 2>&1
+setx TEMPVAR 1 > nul 2>&1
+REG delete HKCU\Environment /F /V TEMPVAR > nul 2>&1
+IF NOT !cmdcmdline! == !CMDLINERUNSTR! (CALL :KillExplorer)
+GOTO ExitBatch
+
+:: -----------------------------------------------------------------------------
+
+:ExitBatch
+ENDLOCAL
+PAUSE
+EXIT /b
+
+:: -----------------------------------------------------------------------------
+
+:AddPath <pathToAdd>
+ECHO %PATH% | FINDSTR /C:"%~1" > nul
+IF ERRORLEVEL 1 (
+	REG add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /f /v PATH /t REG_SZ /d "%PATH%;%~1"  > nul 2>&1
+	IF ERRORLEVEL 0 (
+		ECHO Adding   %1 . . . Success!
+		SET "PATH=%PATH%;%~1"
+		SET UPDATE=1
+	) ELSE (
+		ECHO Adding   %1 . . . FAILED. Run this script with administrator privileges.
+	)	
+) ELSE (
+	ECHO Skipping %1 - Already in PATH
+	)
+EXIT /b
+
+:: -----------------------------------------------------------------------------
+
+:KillExplorer
+
+ECHO Your desktop is being restarted, please wait. . .   
+ping -n 5 127.0.0.1 > NUL 2>&1   
+ECHO Killing process Explorer.exe. . .   
+taskkill /f /im explorer.exe   
+ECHO.   
+ECHO Your desktop is now loading. . .   
+ping -n 5 127.0.0.1 > NUL 2>&1   
+ECHO.   
+ping -n 5 127.0.0.1 > NUL 2>&1   
+START explorer.exe
+START explorer.exe %CD%
+EXIT /b