Step 1: Restart your PC, do not start x Windows
Step 2: $ sudo df-h
you should see/mount on Rootfs (has used 97% or so).
Step 3: $ sudo fdisk/dev/mmcblk0
command: Press P (print)
you should see three partitions, now write down the partition 2 information (/DEV/MMCBLK0P2).
command: Press D (delete partition 2)
command: Press P (print)
you should now see 2 partition
commands: press N (plus partition)
select P (main)
in partition 2 Select 2
first space Enter the beginning of the original partition 2
last Space Enter default value
command: Press P (print)
you should see Partition 2 fill all Space
command: Press W (SAVE)
Step 4: $sudo reboot
after reboot, Using RESIZE2FS to repair partitions 2
Step 5: $ sudo resize2fs/dev/mmcblk0p2
wait about 2-3 minutes
Step 6: $ sudo df-h
you should see/ Attached to ROOTFS (if you use a 8G SD card, you will now only have 22% use)
so you can make the most of the rest of the SD card space.