diff --git a/Tools/autotest/win_sitl/RunCopter.bat b/Tools/autotest/win_sitl/RunCopter.bat
index 9ba69f0317..65a0cfa159 100644
--- a/Tools/autotest/win_sitl/RunCopter.bat
+++ b/Tools/autotest/win_sitl/RunCopter.bat
@@ -2,8 +2,8 @@ rem File run APM:Copter SITL
 SETLOCAL enableextensions
 @echo off
 
-rem Assumes a Cgywin install at C:\cygwin
-if "%CYGWIN_LOCATION%" == "" (set "CYGWIN_LOCATION=C:\cygwin")
+rem Assumes a Cgywin install at C:\cygwin64
+if "%CYGWIN_LOCATION%" == "" (set "CYGWIN_LOCATION=C:\cygwin64")
 
 rem get current dir for Cygwin
 set pth=%CD:~2,99%
diff --git a/Tools/autotest/win_sitl/RunPlane.bat b/Tools/autotest/win_sitl/RunPlane.bat
index abf90eae22..ff5b46263d 100644
--- a/Tools/autotest/win_sitl/RunPlane.bat
+++ b/Tools/autotest/win_sitl/RunPlane.bat
@@ -2,8 +2,8 @@ rem File run APM:Plane SITL
 SETLOCAL enableextensions
 @echo off
 
-rem Assumes a Cgywin install at C:\cygwin
-if "%CYGWIN_LOCATION%" == "" (set "CYGWIN_LOCATION=C:\cygwin")
+rem Assumes a Cgywin install at C:\cygwin64
+if "%CYGWIN_LOCATION%" == "" (set "CYGWIN_LOCATION=C:\cygwin64")
 
 rem get current dir for Cygwin
 set pth=%CD:~2,99%
diff --git a/Tools/autotest/win_sitl/RunRover.bat b/Tools/autotest/win_sitl/RunRover.bat
index 3427acdc77..92dcee186d 100644
--- a/Tools/autotest/win_sitl/RunRover.bat
+++ b/Tools/autotest/win_sitl/RunRover.bat
@@ -2,8 +2,8 @@ rem File run APM:Rover SITL
 SETLOCAL enableextensions
 @echo off
 
-rem Assumes a Cgywin install at C:\cygwin
-if "%CYGWIN_LOCATION%" == "" (set "CYGWIN_LOCATION=C:\cygwin")
+rem Assumes a Cgywin install at C:\cygwin64
+if "%CYGWIN_LOCATION%" == "" (set "CYGWIN_LOCATION=C:\cygwin64")
 
 rem get current dir for Cygwin
 set pth=%CD:~2,99%
diff --git a/Tools/autotest/win_sitl/UpdateAPMSource.bat b/Tools/autotest/win_sitl/UpdateAPMSource.bat
index 057ce18041..9f587621f7 100644
--- a/Tools/autotest/win_sitl/UpdateAPMSource.bat
+++ b/Tools/autotest/win_sitl/UpdateAPMSource.bat
@@ -2,6 +2,9 @@ rem File to update the APM source
 rem Assumes a Cgywin install at C:\cygwin
 @echo off
 
+rem Assumes a Cgywin install at C:\cygwin64
+if "%CYGWIN_LOCATION%" == "" (set "CYGWIN_LOCATION=C:\cygwin64")
+
 rem get current dir for Cygwin
 set pth=%CD:~2,99%
 set pth=%pth:\=/%
@@ -9,9 +12,9 @@ set drv=%CD:~0,1%
 set "fullpath=/cygdrive/%drv%%pth%"
 
 rem update the source
-C:\cygwin\bin\bash.exe --login -i -c "cd ""%fullpath%"" && cd ../../../ && git pull && git submodule update --init --recursive"
+%CYGWIN_LOCATION%\bin\bash.exe --login -i -c "cd ""%fullpath%"" && cd ../../../ && git pull && git submodule update --init --recursive"
 
 rem re-configure build config
-C:\cygwin\bin\bash.exe --login -i -c "cd ""%fullpath%"" && cd ../../../ && ./modules/waf/waf-light configure --board=sitl"
+%CYGWIN_LOCATION%\bin\bash.exe --login -i -c "cd ""%fullpath%"" && cd ../../../ && ./modules/waf/waf-light configure --board=sitl"
 
 pause
diff --git a/Tools/autotest/win_sitl/readme.txt b/Tools/autotest/win_sitl/readme.txt
index b056cc128d..f9d2a0419f 100644
--- a/Tools/autotest/win_sitl/readme.txt
+++ b/Tools/autotest/win_sitl/readme.txt
@@ -15,4 +15,4 @@ To continue with the current EEPROM, run:
 To update the APM code with the latest of Github, run UpdateAPMSource.bat. Note this is bleeding-edge source code and some bugs may be present.
 Deleting the SITL environment
 
-To uninstall/delete the SITL environment, simply delete the "cygwin" folder in the C:\ drive.
+To uninstall/delete the SITL environment, simply delete the "cygwin64" folder in the C:\ drive.