diff --git a/backup_new.sh b/backup_new.sh
index 9b2148e..dac9f25 100755
--- a/backup_new.sh
+++ b/backup_new.sh
@@ -247,6 +247,18 @@ while [ $# -gt 0 ]; do
 done
 
 
+### check pre-requisites and default values
+# does the details file exist?
+if [ ! -f "$configDetails" ]; then
+    badParam dne "(-c default)" "$configDetails"
+fi
+# is borg installed?
+command -v borg > /dev/null || \
+    printf "\n${err}ERROR: BORG is not installed on this system!${norm}\n\n"
+exit 3
+
+
+
 ### start logging
 printf "${mag}[%s] --- Start %s execution ---${norm}\n" \
     "$(stamp)" "$scriptName" >> "$logFile"
@@ -268,6 +280,7 @@ exit 0
 ### error codes
 # 1: parameter error
 # 2: not run as root
+# 3: borg not installed
 # 100: could not start seafile service
 # 101: could not start seahub service
 # 102: could not stop seafile service