diff --git a/jhalfs b/jhalfs
index d4818d4..2a8b0e2 100755
--- a/jhalfs
+++ b/jhalfs
@@ -327,6 +327,10 @@ _IS_()  # Function to test build scripts names
 #----------------------------#
 chapter4_Makefiles() {
 #----------------------------#
+
+# If /home/lfs is already present in the host, we asume that the
+# lfs user and group are also presents in the host, and a backup
+# of their bash init files is made.
 (
     cat << EOF
 020-creatingtoolsdir:
@@ -338,14 +342,24 @@ chapter4_Makefiles() {
 
 021-addinguser:  020-creatingtoolsdir
 	@\$(call echo_message, Building)
-	@groupadd lfs && \\
-	useradd -s /bin/bash -g lfs -m -k /dev/null lfs && \\
-	chown lfs \$(LFS)/tools && \\
+	@if [ ! -d /home/lfs ]; then \\
+		groupadd lfs; \\
+		useradd -s /bin/bash -g lfs -m -k /dev/null lfs; \\
+	else \\
+		touch user-lfs-exist; \\
+	fi;
+	@chown lfs \$(LFS)/tools && \\
 	chown lfs \$(LFS)/sources && \\
 	touch \$@
 
 022-settingenvironment:  021-addinguser
 	@\$(call echo_message, Building)
+	@if [ -f /home/lfs/.bashrc -a ! -f /home/lfs/.bashrc.XXX ]; then \\
+		mv -v /home/lfs/.bashrc /home/lfs/.bashrc.XXX; \\
+	fi;
+	@if [ -f /home/lfs/.bash_profile  -a ! -f /home/lfs/.bash_profile.XXX ]; then \\
+		mv -v /home/lfs/.bash_profile /home/lfs/.bash_profile.XXX; \\
+	fi;
 	@echo "set +h" > /home/lfs/.bashrc && \\
 	echo "umask 022" >> /home/lfs/.bashrc && \\
 	echo "LFS=/mnt/lfs" >> /home/lfs/.bashrc && \\
@@ -819,28 +833,30 @@ all:  chapter4 chapter5 chapter6 chapter789
 
 chapter4:  020-creatingtoolsdir 021-addinguser 022-settingenvironment
 
-chapter5:  chapter4 $chapter5
+chapter5:  chapter4 $chapter5 restore-lfs-env
 
 chapter6:  chapter5 $chapter6
 
 chapter789:  chapter6 $chapter789
 
 clean-all:  clean
-	rm -rf ./*
+	rm -rf ./{commands,logs,Makefile,dump-lfs-scripts.xsl,functions,packages,patches}
 
 clean:  clean-chapter789 clean-chapter6 clean-chapter5 clean-chapter4
 
 clean-chapter4:
-	-userdel lfs
-	rm -rf /home/lfs
+	-if [ ! -f user-lfs-exist ]; then \\
+		userdel lfs; \\
+		rm -rf /home/lfs; \\
+	fi;
 	rm -rf \$(LFS)/tools
 	rm -f /tools
-	rm -f envars
+	rm -f envars user-lfs-exist
 	rm -f 02* logs/02*.log
 
 clean-chapter5:
 	rm -rf \$(LFS)/tools/*
-	rm -f $chapter5
+	rm -f $chapter5 restore-lfs-env sources-dir
 	cd logs && rm -f $chapter5 && cd ..
   
 clean-chapter6:
@@ -857,6 +873,16 @@ clean-chapter789:
 	rm -f $chapter789
 	cd logs && rm -f $chapter789 && cd ..
 
+restore-lfs-env:
+	@\$(call echo_message, Building)
+	@if [ -f /home/lfs/.bashrc.XXX ]; then \\
+		mv -fv /home/lfs/.bashrc.XXX /home/lfs/.bashrc; \\
+	fi;
+	@if [ -f /home/lfs/.bash_profile.XXX ]; then \\
+		mv -v /home/lfs/.bash_profile.XXX /home/lfs/.bash_profile; \\
+	fi;
+	@chown lfs:lfs /home/lfs/.bash* && \\
+	touch \$@
 
 EOF
 ) >> $MKFILE