diff --git a/build.sh b/build.sh
index 8129294..6d926fe 100644
--- a/build.sh
+++ b/build.sh
@@ -5,7 +5,6 @@ pkgname=librewolf
 _pkgname=LibreWolf
 
 pkgver=85.0
-#srcdir=/c/mozilla-source
 
 
 
@@ -23,8 +22,6 @@ fetch() {
 
 
 
-
-
 prepare() {
     rm -rf firefox-$pkgver
     tar xf firefox-$pkgver.source.tar.xz
@@ -69,31 +66,39 @@ mk_add_options MOZ_TELEMETRY_REPORTING=0
 END
 
 
+
     patch -p1 -i ../remove_addons.patch
     patch -p1 -i ../megabar.patch
     patch -p1 -i ../unity-menubar.patch
 
 
-  
+
     # Disabling Pocket
     sed -i "s/'pocket'/#'pocket'/g" browser/components/moz.build
     # this one only to remove an annoying error message:
     sed -i 's#SaveToPocket.init();#// SaveToPocket.init();#g' browser/components/BrowserGlue.jsm
 
 
-    
+
     # Remove Internal Plugin Certificates
     _cert_sed='s#if (aCert.organizationalUnit == "Mozilla [[:alpha:]]\+") {\n'
     _cert_sed+='[[:blank:]]\+return AddonManager\.SIGNEDSTATE_[[:upper:]]\+;\n'
     _cert_sed+='[[:blank:]]\+}#'
     _cert_sed+='// NOTE: removed#g'
-	
-    # FIXME: on windows: the sed.exe in MozBuild is too old, no -z, using the one from Git instead.
-    mysed='/c/mozilla-source/Git/usr/bin/sed.exe'
+    # on windows: the sed.exe in MozBuild is too old, no -z, using the one from Git instead.
+    if [ -f '/c/mozilla-build/start-shell.bat' ]; then
+	mysed='/c/mozilla-source/Git/usr/bin/sed.exe'
+	if [ ! -f $mysed ]; then
+	    echo 'build.sh: For the build to work, copy "c:\program files\Git" folder into "c:\mozilla-source".'
+	    exit
+	fi
+    else
+	$mysed='sed'
+    fi
     $mysed -z "$_cert_sed" -i toolkit/mozapps/extensions/internal/XPIInstall.jsm
 
 
-  
+
     # allow SearchEngines option in non-ESR builds
     sed -i 's#"enterprise_only": true,#"enterprise_only": false,#g' browser/components/enterprisepolicies/schemas/policies-schema.json
 
@@ -107,28 +112,25 @@ END
 
 
 
-    
     cp -r ../common/source_files/* ./
+
     # FIXME: this 'mozconfig' file in the 'common' submodule should be removed
-    # this submodule is purely for the branding. I imagine that we want the
-    # missing_branding_files into the 'common' submodule.
+    # this submodule is purely for the branding.
     rm -f mozconfig
 
-    # FIX: on windows: the stubinstaller folder is missing from the librewolf branding folder.
+    # FIXME: on windows: the stubinstaller folder is missing from the librewolf branding folder.
+    # this might be a bug in FF however as it seems to take missing branding resources from
+    # the nightly branding. We probably want this stuff merged into the 'common' submodule.
     cp -r ../missing_branding_files/stubinstaller browser/branding/librewolf
 
     # just a straight copy for now..
     cp ../mozconfig .mozconfig
-    
+
     cd ..
 }
 
 
 
-
-
-
-
 build() {
     cd firefox-$pkgver
 
@@ -138,13 +140,21 @@ build() {
 }
 
 
+
 package() {
     cd firefox-$pkgver
 
     ./mach package
 
+    cd ..
+}
+
+installer_win() {
+    cd firefox-$pkgver
+    
     # apply the LibreWolf settings
     cp -rv ../settings/* obj-x86_64-pc-mingw32/dist/librewolf
+    
     # recreate the zip file..
     cd obj-x86_64-pc-mingw32/dist
     rm -f librewolf-$pkgver.en-US.win64.txt librewolf-$pkgver.en-US.win64.zip
@@ -152,19 +162,26 @@ package() {
     /c/mozilla-source/Git/usr/bin/sha256sum.exe librewolf-$pkgver.en-US.win64.zip > librewolf-$pkgver.en-US.win64.zip.sha256sum
     cp librewolf-$pkgver.en-US.win64.zip* ../../..
     cd ../..
-    
+
+    cd ..
+}
+
+installer_macos() {
+    cd firefox-$pkgver
+
+    # TODO: we want to apply the librewolf settings and make the .dmg file here.
+    echo 'build.sh: installer_macos() Not implemented yet.'
     cd ..
 }
 
 
 
-
-
-
 # windows: change $PATH to find all the build tools in .mozbuild
-# this might do the trick on macos aswell
-export TPATH=$HOME/.mozbuild/clang/bin:$HOME/.mozbuild/cbindgen:$HOME/.mozbuild/node:$HOME/.mozbuild/nasm
-export PATH=$TPATH:$PATH
+# this might do the trick on macos aswell?
+if [ -f '/c/mozilla-build/start-shell.bat' ]; then
+    export TPATH=$HOME/.mozbuild/clang/bin:$HOME/.mozbuild/cbindgen:$HOME/.mozbuild/node:$HOME/.mozbuild/nasm
+    export PATH=$TPATH:$PATH
+fi
 
 
 
@@ -186,8 +203,16 @@ if [[ "$*" == *package* ]]; then
     package
     done_something=1
 fi
-
-if (( done_something == 0 )); then
-    echo "Usage: $0 fetch | prepare | build | package"
+if [[ "$*" == *installer_win* ]]; then
+    installer_win
+    done_something=1
+fi
+if [[ "$*" == *installer_macos* ]]; then
+    installer_macos
+    done_something=1
 fi
 
+if (( done_something == 0 )); then
+    echo "Usage: $0 fetch | prepare | build | package | installer_win | installer_mac"
+    exit
+fi