diff --git a/src/usbinstall.sh b/src/usbinstall.sh
index 4d1cf56..92b53ae 100755
--- a/src/usbinstall.sh
+++ b/src/usbinstall.sh
@@ -230,7 +230,7 @@ if [ "$CONFIRM" = "1" ]; then
 	echo $"Warning: You are going to format this device ($1). Are you sure to continue? [yes/no]"
 	read KEY
 		case "$KEY" in
-			$yes)
+			$"yes"|"Y"|"y")
 				;;
 			*)
 				errorAndExit $"Installation aborted"
@@ -240,11 +240,23 @@ fi
 
 set_status $"Partitioning $SELECT_USB..."
 echo $"Partitioning $SELECT_USB..."
-sudo parted $SELECT_USB mktable msdos -s &>>$LOGFILE
+# Start from a new partition table
+sudo parted -s $SELECT_USB mktable msdos &>>$LOGFILE
 if [ "$?" != "0" ]; then
    errorAndExit $"Error:"" \"parted\" "$"exit with error (see $LOGFILE)"
 fi
-sudo parted -s -- $SELECT_USB mkpart primary ext4 0 -1 &>>$LOGFILE
+# EFI partition
+sudo parted -s -- $SELECT_USB mkpart primary fat32 0 20M &>>$LOGFILE
+if [ "$?" != "0" ]; then
+   errorAndExit $"Error:"" \"parted\" "$"exit with error (see $LOGFILE)"
+fi
+# openmamba partition
+sudo parted -s -- $SELECT_USB mkpart primary ext4 20M -1 &>>$LOGFILE
+if [ "$?" != "0" ]; then
+   errorAndExit $"Error:"" \"parted\" "$"exit with error (see $LOGFILE)"
+fi
+# boot flag on openmamba partition
+sudo parted -s -- $SELECT_USB set 2 boot on &>>$LOGFILE
 if [ "$?" != "0" ]; then
    errorAndExit $"Error:"" \"parted\" "$"exit with error (see $LOGFILE)"
 fi
@@ -253,21 +265,24 @@ set_pbar 5
 
 set_status $"Formatting $SELECT_USB..."
 echo $"Formatting $SELECT_USB..."
-sudo mkfs.ext4 ${SELECT_USB}1 -L openmamba_live &>>$LOGFILE
+sudo mkfs.vfat ${SELECT_USB}1 -n EFI &>>$LOGFILE
+if [ "$?" != "0" ]; then
+   errorAndExit $"Error:"" \"mkfs.vfat\" "$"exit with error (see $LOGFILE)"
+fi
+sudo mkfs.ext4 ${SELECT_USB}2 -L openmamba_live &>>$LOGFILE
 if [ "$?" != "0" ]; then
    errorAndExit $"Error:"" \"mkfs.ext4\" "$"exit with error (see $LOGFILE)"
 fi
 
 sleep 1
-LANG=C udisks --mount ${SELECT_USB}1 &>>$LOGFILE
+LANG=C udisks --mount ${SELECT_USB}2 &>>$LOGFILE
 if [ "$?" != "0" ]; then
    errorAndExit $"Error:"" \"udisks --mount\" "$"exit with error (see $LOGFILE)"
 fi
 set_pbar 30
 
-
 # Riceve la mountdir della chiavetta da dbus
-MOUNTDIR=`dbus_properties_get_stringlist org.freedesktop.UDisks /org/freedesktop/UDisks/devices/${SELECT_USB/*\/}1 \
+MOUNTDIR=`dbus_properties_get_stringlist org.freedesktop.UDisks /org/freedesktop/UDisks/devices/${SELECT_USB/*\/}2 \
 org.freedesktop.UDisks.Device DeviceMountPaths`
 
 if [ ! -d "$MOUNTDIR" ]; then
@@ -316,8 +331,8 @@ set_pbar 98
 
 set_status $"Unmount usb device"
 echo $"Unmount usb device"
-LANG=C udisks --unmount ${SELECT_USB}1 |  grep failed && { 
-	errorAndExit $"Error: fail to umount the usb key (${SELECT_USB}1)"
+LANG=C udisks --unmount ${SELECT_USB}2 |  grep failed && { 
+	errorAndExit $"Error: fail to umount the usb key (${SELECT_USB}2)"
 }
 set_pbar 100
 exit_frontend ""