diff --git a/packaging/win32/README b/packaging/win32/README
index 6bc0b0b6d9..a977b71e5f 100644
--- a/packaging/win32/README
+++ b/packaging/win32/README
@@ -5,7 +5,8 @@ For cross-compiling the windows executable on Linux, see the lower
 section of this file.
 
 Before you start with the automated build, you have to complete these
-steps manually. The directory variables are set in custom.sh.
+steps manually. The directory variables are set in `defaults' and optionally
+`custom'.
 
 * Download MSYS (but *only* msys; no mingw and no msysdtk)
 from http://www.mingw.org/download.shtml -> Current -> MSYS -> (bin, *.exe)
@@ -18,13 +19,9 @@ to $MSYS_DIR
 from http://www.mingw.org/download.shtml -> Current -> mingwPORT -> (bin, wget-*)
 to $DOWNLOAD_DIR
 
-* Adjust custom.sh (install.sh doesn't need to be changed). In
-  custom.sh you should adapt the directory variables. If you want to,
-  you could also comment out those build steps that have been
-  completed already and/or should not be performed now, although the
-  script is quite intelligent not to duplicate already completed
-  work. If you want verbose output of any script step, change the
-  first line in install.sh and add the "-x" switch.
+* Look at defaults and optionally create a file named custom to specify
+  adapted directory variables.  If you want verbose output of any script
+  step, add "set -x" to custom.
 
 Start/Enter any MSYS shell window. Let the automated build begin by:
 
@@ -57,19 +54,19 @@ These steps need to be performed:
    script create_cross_mingw.sh - it will
    download, compile, and install a mingw32 toolchain.
 
-2. Edit the file custom.sh: Make a globale search-and-replace of
+2. Edit the file defaults: Make a global search-and-replace of
    '\\' into '/' so that all directories are specified in unix
    conventions. Set the variable cross_compile to "yes". Then
-   adjust the directories in custom.sh according to your
+   adjust the directories in defaults according to your
    preferred installation, especially $GLOBAL_DIR.
 
 3. Download a binary windows packages for "guile" e.g. from
    http://www.tu-harburg.de/~et2cs/gnc/ and unpack it into the
-   directory $GUILE_DIR as given in custom.sh. (This is done because
+   directory $GUILE_DIR as given in defaults. (This is done because
    the build system for guile doesn't support cross-compiling.)
 
 4. Call install.sh, which will read the directory settings from
-   custom.sh. It should download, compile, and install everything
+   defaults. It should download, compile, and install everything
    automatically. Eventually the windows gnucash is installed into
    $GNUCASH_DIR. 
 
diff --git a/packaging/win32/custom.sh b/packaging/win32/defaults
similarity index 93%
rename from packaging/win32/custom.sh
rename to packaging/win32/defaults
index ee21fb2ef5..42e2b86b2d 100644
--- a/packaging/win32/custom.sh
+++ b/packaging/win32/defaults
@@ -1,9 +1,17 @@
 #!/bin/sh # for emacs
 #
-# all directories should be without spaces!
+# Instead of just editing this file, it is recommended to create a file `custom'
+# in the same directory that will be read in at the end of this script.
+#
+# You can use the full power of bash 2.04 scripting.  In particular you can
+# override any variable set here, add steps (use add_step <step> and implement
+# function <step>()), remove steps (use remove_step <step>) and more.
+# Keep in mind that this might render install.sh & friends non-functional.
+#
+# Note: All directories must be without spaces!
 
-[ "$__SOURCED_CUSTOM_SH" ] && return
-__SOURCED_CUSTOM_SH=1
+[ "$__SOURCED_DEFAULTS" ] && return
+__SOURCED_DEFAULTS=1
 
 GLOBAL_DIR=c:\\soft
 TMP_DIR=$GLOBAL_DIR\\tmp
@@ -250,3 +258,8 @@ add_step inst_svn
 add_step svn_up
 add_step inst_gnucash
 add_step inst_docs
+
+
+### read custom
+[ -f "custom" ] && . custom || true
+### end of script
diff --git a/packaging/win32/dist.sh b/packaging/win32/dist.sh
index 70b5562940..36b8484d33 100644
--- a/packaging/win32/dist.sh
+++ b/packaging/win32/dist.sh
@@ -8,7 +8,7 @@ function unix_path() { echo "$*" | sed 's,^\([A-Za-z]\):,/\1,;s,\\,/,g'; }
 
 qpushd "$(dirname $(unix_path "$0"))"
 . functions
-. custom.sh
+. defaults
 
 register_env_var PATH ":"
 
diff --git a/packaging/win32/functions b/packaging/win32/functions
index 05f9ceb33a..4567c78453 100644
--- a/packaging/win32/functions
+++ b/packaging/win32/functions
@@ -2,6 +2,17 @@
 __SOURCED_FUNCTIONS=1
 
 function add_step() { steps=("${steps[@]}" "$@"); }
+function remove_step() {
+    while [ "$1" ]; do
+        _steps=("${steps[@]}")
+        unset steps
+        for _step in "${_steps[@]}"; do
+            [ "$_step" != "$1" ] && add_step $_step
+        done
+        shift
+    done
+    unset _steps
+}
 function quiet() { "$@" &>/dev/null; }
 
 # c:/dir/sub
diff --git a/packaging/win32/install.sh b/packaging/win32/install.sh
index 79fd940bc5..b1866864ea 100644
--- a/packaging/win32/install.sh
+++ b/packaging/win32/install.sh
@@ -8,7 +8,7 @@ function unix_path() { echo "$*" | sed 's,^\([A-Za-z]\):,/\1,;s,\\,/,g'; }
 
 qpushd "$(dirname $(unix_path "$0"))"
 . functions
-. custom.sh
+. defaults
 
 register_env_var ACLOCAL_FLAGS " "
 register_env_var AUTOTOOLS_CPPFLAGS " "
diff --git a/packaging/win32/reset.sh b/packaging/win32/reset.sh
index cdddc58a08..379bfc9ba7 100644
--- a/packaging/win32/reset.sh
+++ b/packaging/win32/reset.sh
@@ -2,7 +2,7 @@
 
 set -e
 
-####  Load Custom.sh
+####  Load defaults
 
 function qpushd() { pushd "$@" >/dev/null; }
 function qpopd() { popd >/dev/null; }
@@ -10,7 +10,7 @@ function unix_path() { echo "$*" | sed 's,^\([A-Za-z]\):,/\1,;s,\\,/,g'; }
 
 qpushd "$(dirname $(unix_path "$0"))"
 . functions
-. custom.sh
+. defaults
 
 ## too bad, bash 2.04 has no real support for arrays