diff --git a/install-debian.sh b/install-debian.sh
old mode 100644
new mode 100755
index 23a3c45..fa07601
--- a/install-debian.sh
+++ b/install-debian.sh
@@ -1,9 +1,10 @@
 #!/usr/bin/env bash
 
-# hotfix for strange strato configuration
-# Copyright (C) 2017 Andreas Fendt - All Rights Reserved
+# Install Script for Debian and Ubuntu installations
+# This script can be called multiple times
+# Copyright (C) 2018 Andreas Fendt - All Rights Reserved
 # Permission to copy and modify is granted under the MIT license
-# Last revised 18.11.2017
+# Last revised 28.04.2018
 
 # check if root
 if [[ $EUID -ne 0 ]]; then
@@ -13,7 +14,7 @@ fi
 
 # check if debian
 if [ ! "$(grep -Ei 'debian|buntu' /etc/*release)" ]; then
-    echo "This script must be run on a debian system" 1>&2
+    echo "This script must be run on a debian or ubuntu system" 1>&2
     exit 1
 fi
 
@@ -22,42 +23,38 @@ apt-get update -y
 apt-get dist-upgrade -y
 apt-get autoclean -y
 
-# get users directory
+# get users directory and usernames
+root_user=$(grep ':0:' /etc/passwd | awk -F':' '{print $1}')
 root_user_path=$(grep ':0:' /etc/passwd | awk -F':' '{print $6}')
 default_user_path=$(egrep '\:100[0-9]\:' /etc/passwd | tail -n 1 | awk -F':' '{print $6}')
 default_user=$(egrep '\:100[0-9]\:' /etc/passwd | tail -n 1 | awk -F':' '{print $1}')
 
-# default shell
-apt-get install -y sudo mc tree pv vim bash-completion
+# install default packages
+apt-get install -y sudo mc tree pv vim bash-completion wget git htop iotop iftop nmon apt-file aptitude hexedit tmux \
+                   fonts-powerline
 
 # zsh shell
-apt-get install -y zsh && (
-    sed -i -- 's/\/bin\/bash/\/bin\/zsh/' /etc/passwd
-    wget -O /etc/zsh/newuser.zshrc.recommended \
-            http://git.grml.org/f/grml-etc-core/etc/zsh/zshrc
-    cp -f /etc/zsh/newuser.zshrc.recommended ${default_user_path}/.zshrc
-    cp -f /etc/zsh/newuser.zshrc.recommended ${root_user_path}/.zshrc
+apt-get install -y zsh && ( [ ! -d $root_user_path/.oh-my-zsh ] || [ ! -d $default_user_path/.oh-my-zsh ] ) && (
+    # change shell
+    chsh -s /bin/zsh $root_user
+    chsh -s /bin/zsh $default_user
+    
+    # install oh-my-zsh
+    sh -c "$(wget https://raw.githubusercontent.com/robbyrussell/oh-my-zsh/master/tools/install.sh -O -)"
+    
+    # configure oh-my-zsh
+    grep 'ZSH_THEME="agnoster"' $root_user_path/.zshrc || sed -i -- 's/ZSH_THEME=".*"/ZSH_THEME="agnoster"/g' $root_user_path/.zshrc
+    grep "command-not-found" $root_user_path/.zshrc || sed -i -- '/^plugins=(/a \\  command-not-found\n  common-aliases\n  sudo\n  systemd\n  tmux\n  ubuntu' $root_user_path/.zshrc
+   
+    # install oh-my-zsh to default user
+    cp $root_user_path/.zshrc $default_user_path/.zshrc
+    cp -a $root_user_path/.oh-my-zsh $default_user_path/.oh-my-zsh
+    chown ${default_user}:${default_user} ${default_user_path}/.oh-my-zsh ${default_user_path}/.zshrc
+    
+    # configure tmux
+    grep "ZSH_TMUX_AUTOSTART" $default_user_path/.zshrc || sed -i -- '1s/^/ZSH_TMUX_AUTOSTART="true"\nZSH_TMUX_AUTOQUIT="false"\n\n/' $default_user_path/.zshrc
 )
 
-# add tmux auto start
-apt-get install -y tmux && (
-    echo 'if [ "$TMUX" = "" ]; then tmux; fi' | cat - ${default_user_path}/.zshrc > \
-        /tmp/.zshrc && mv /tmp/.zshrc ${default_user_path}/.zshrc
-)
-
-# diagnostics
-apt-get install -y htop iotop iftop nmon powertop stress lm-sensors \
-                   gddrescue smartmontools kpartx nmap
-
-# programming
-apt-get install -y git build-essential
-
-# networking
-apt-get install -y axel wget ethtool fping
-
-# misc. tools
-apt-get install -y apt-file aptitude hexedit manpages-de
-
 # configure vim
 touch ${root_user_path}/.vimrc ${default_user_path}/.vimrc
 for config in "filetype plugin indent on" "set tabstop=4" "set shiftwidth=4" \
@@ -66,16 +63,14 @@ for config in "filetype plugin indent on" "set tabstop=4" "set shiftwidth=4" \
     grep "$config" ${root_user_path}/.vimrc || echo "$config" >> ${root_user_path}/.vimrc
     grep "$config" ${default_user_path}/.vimrc || echo "$config" >> ${default_user_path}/.vimrc
 done
-
-# configure user files
-chown ${default_user}:${default_user} ${default_user_path}/.vimrc ${default_user_path}/.zshrc
+chown ${default_user}:${default_user} ${default_user_path}/.vimrc
 
 # configure tmux
-cat > /etc/tmux.conf <<EOL
-bind '"' split-window -c "#{pane_current_path}"
-bind % split-window -h -c "#{pane_current_path}"
-bind c new-window -c "#{pane_current_path}"
-EOL
+for config in "bind '\"' split-window -c \"#{pane_current_path}\"" \
+              "bind % split-window -h -c \"#{pane_current_path}\"" \
+              "bind c new-window -c \"#{pane_current_path}\""; do
+    grep "$config" /etc/tmux.conf || echo "$config" >> /etc/tmux.conf
+done
 
 # configure system
 apt-get install -y console-data console-setup locales \
diff --git a/unattended-upgrades.sh b/unattended-upgrades.sh
old mode 100644
new mode 100755