diff --git a/once/install.bat b/once/install.bat
index 7d9a8cd..3dde082 100755
--- a/once/install.bat
+++ b/once/install.bat
@@ -1,5 +1,7 @@
 @echo off
 
+if "!%SYSROOT%!"=="!!" goto sysroot_missing
+
 pushd "%~dp0"
 
 set shell_sysroot=%cd%
@@ -20,3 +22,16 @@ start bin\ntctty.exe --sysroot %shell_sysroot% --exec /bin/mintty -d -h always -
 popd
 
 exit
+
+:sysroot_missing
+
+echo.
+echo !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+echo this is the @product@ installation script
+echo SYSROOT not set! Will do nothing...
+echo !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+echo.
+
+@pause
+
+exit /B 1