Index: /trunk/src/VBox/Additions/linux/installer/vboxadd.sh
===================================================================
--- /trunk/src/VBox/Additions/linux/installer/vboxadd.sh	(revision 43748)
+++ /trunk/src/VBox/Additions/linux/installer/vboxadd.sh	(revision 43749)
@@ -360,7 +360,9 @@
 cleanup_modules()
 {
-    begin "Removing existing VirtualBox DKMS kernel modules"
-    $DODKMS uninstall $OLDMODULES > $LOG
-    succ_msg
+    if [ -n "$(which dkms 2>/dev/null)" ]; then
+        begin "Removing existing VirtualBox DKMS kernel modules"
+        $DODKMS uninstall $OLDMODULES > $LOG
+        succ_msg
+    fi
     begin "Removing existing VirtualBox non-DKMS kernel modules"
     for i in $OLDMODULES; do
@@ -378,5 +380,6 @@
 
     # Short cut out if a dkms build succeeds
-    if $DODKMS install vboxguest $INSTALL_VER >> $LOG 2>&1; then
+    if [ -n "$(which dkms 2>/dev/null)" ] &&
+       $DODKMS install vboxguest $INSTALL_VER >> $LOG 2>&1; then
         succ_msg
         return 0