diff --git a/home/-shrc b/home/-shrc
index a1e2ae6..e960044 100644
--- a/home/-shrc
+++ b/home/-shrc
@@ -1,6 +1,10 @@
 #!/usr/bin/env false
 # for ash, dash, bash, and zsh.
+
 [ -n "$ZSH_VERSION" -o -n "$BASH_VERSION" ] && FANCY=1 || FANCY=0
+if [ "$FANCY" = 0 ]; then
+    . ~/.prep # handle boring stuff like /etc/profile and $PATH
+fi
 
 # {{{1 utilities
 
@@ -66,7 +70,7 @@ fi
 
 # enable colors {{{2
 
-if [ "$FANCY" -eq 1 ]; then
+if [ "$FANCY" = 1 ]; then
     # busybox is smart enough to ignore --color flags when unsupported.
     alias grep='grep --color=auto'
     alias ls='ls --color=auto'
diff --git a/home/bashrc b/home/bashrc
index f02965f..7c0fbd4 100644
--- a/home/bashrc
+++ b/home/bashrc
@@ -1,4 +1,5 @@
 [ -z "$PS1" ] && return
+. ~/.prep # handle boring stuff like /etc/profile and $PATH
 
 HISTCONTROL=erasedups
 HISTSIZE=1000
diff --git a/home/prep b/home/prep
new file mode 100644
index 0000000..b0c0f4a
--- /dev/null
+++ b/home/prep
@@ -0,0 +1,52 @@
+#!/usr/bin/env false
+# for ash, dash, bash, and zsh.
+
+if [ -r /etc/msystem ]; then
+    # avoid sourcing /etc/profile because forking cygwin processes is awful.
+    . /etc/msystem # this doesn't fork anything, thankfully.
+
+    # NOTE: never inherits parent process's PATH. does not add perl paths.
+    PATH="/usr/local/bin:/usr/bin:/bin"
+    PATH="$PATH:/c/Windows/System32:/c/Windows:/c/Windows/System32/Wbem"
+    PATH="$PATH:/c/Windows/System32/WindowsPowerShell/v1.0/"
+    MANPATH="/usr/local/man:/usr/share/man:/usr/man:/share/man"
+    INFOPATH="/usr/local/info:/usr/share/info:/usr/info:/share/info"
+    SYSCONFDIR="${SYSCONFDIR:-/etc}" # not exported for some reason?
+
+    CONFIG_SITE="/etc/config.site"
+    SHELL="/usr/bin/zsh"
+
+    if [ "$MSYSTEM" = MSYS ]; then
+        PATH="$PATH:/opt/bin"
+        PKG_CONFIG_PATH="/usr/lib/pkgconfig:/usr/share/pkgconfig:/lib/pkgconfig"
+    else
+        PATH="$MINGW_PREFIX/bin:$PATH"
+        PKG_CONFIG_PATH="$MINGW_PREFIX/lib/pkgconfig:$MINGW_PREFIX/share/pkgconfig"
+        export ACLOCAL_PATH="$MINGW_PREFIX/share/aclocal:/usr/share/aclocal"
+        MANPATH="$MINGW_PREFIX/local/man:$MINGW_PREFIX/share/man:$MANPATH"
+    fi
+
+    [ -n "${USER:=$USERNAME}" ] || USER="$(exec id -un)" # not much choice here
+    [ -n "${HOSTNAME:=$HOST}" ] || HOSTNAME="$(exec /usr/bin/hostname)"
+
+    LANG="en_US.UTF-8"
+    [ -s /etc/localtime ] && TZ=":/etc/localtime" || TZ="America/Vancouver"
+
+    TMP="/tmp"; TEMP="/tmp"
+    tmp="C:\\Users\\$USER\\AppData\\Local\\Temp"; temp="$tmp"
+    ORIGINAL_TMP="/c/Users/$USER/AppData/Local/Temp"; ORIGINAL_TEMP="$ORIGINAL_TMP"
+    export CONFIG_SITE HOSTNAME INFOPATH LANG MANPATH ORIGINAL_TEMP ORIGINAL_TMP PATH PKG_CONFIG_PATH SHELL TEMP TMP TZ USER temp tmp
+
+elif [ -r /etc/profile ]; then
+    if [ -n "$ZSH_VERSION" ]; then
+        emulate sh -c "source /etc/profile"
+    else
+        . /etc/profile
+    fi
+
+else # something's strange; set some sane defaults (from alpine)
+    export PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
+    export CHARSET="UTF-8"
+    export LANG="C.UTF-8"
+    export LC_COLLATE="C"
+fi
diff --git a/home/zshrc b/home/zshrc
index 8b94d7f..8c91435 100644
--- a/home/zshrc
+++ b/home/zshrc
@@ -1,4 +1,4 @@
-[ -e /etc/profile ] && emulate sh -c "source /etc/profile"
+. ~/.prep # handle boring stuff like /etc/profile and $PATH
 
 HISTFILE=~/.histfile
 HISTSIZE=99999
diff --git a/install b/install
index 3ae9b62..9838bda 100755
--- a/install
+++ b/install
@@ -130,7 +130,7 @@ cd "${HOME:?HOME variable empty or unset}" || die "failed to change directory"
 backup_dir="$rc/backup-$(date -u '+%s')"
 [ ! -d "$backup_dir" ] || die "backup directory already exists"
 
-for f in .bashrc .zshrc .-shrc .prezto-compinit .ls_colors \
+for f in .bashrc .zshrc .prep .-shrc .prezto-compinit .ls_colors \
   .vimrc .inputrc .Xresources .screenrc .tmux.conf; do
     hardlink "$f" "$rc/home/${f#.}"
 done