Is there any possible (and simple) way to delete my Windows partitions and extend my Ubuntu partitions?

I want to know is there any possible (and simple) way to delete my Windows partitions and extend my Ubuntu partitions.

I have 1 HDD 700 GB:

• sda1 primary 100MB NTFS (Windows boot partition)
• sda2 primary 100GB NTFS (Windows 7 OS)
• sda3 primary 500GB NTFS (Windows data files)
• sda4 extended partition 98GB:
• sda6 ext4 94GB (Ubuntu 12.04)
• sda5 swap 4GB

My actual boot partition is sda1

I want do delete Windows partitions and extend my Ubuntu installation to the whole HDD, maybe creating only /home and /boot partition additional, so I have:

• sda1 /boot partition (500MB)
• sda2 / partition (200GB)
• sda3 /home partition (489,5GB)
• sda4 swap (10GB)

Is there any way to do it without reinstall whole system ?

Solution 1:

Note: You'll have to do this from a live USB/live DVD.

CAUTION: This will wipe data off the windows partition(s), and possibly (although very unlikely) your Ubuntu ones as well.

Open up GParted (click on dock, type in "partition"), type in your password. Right click on your Windows partition(s) and click on delete. Apply changes. After that right click on your Ubuntu partition(s) and click on re-size/move, re-size your partition by dragging either side of the bar. Move the partition by dragging the bar itself. Apply changes, and you're done. Reboot into your main Ubuntu, and enjoy.

As for the /home and /boot, read these:

making /boot partition after install

making /home partition after install