How to seperate hard disk drives?

Friends,I just tried to install ubuntu on my pc.My hard disk is of 80gb.Now when i uninstalled it and installed windows 7 the ubuntu combinded my hard drives to one drive of 74.5gb.now i want to seperate it in to total four drives of 19.5 gb.How to do this.

 

Use a program such as the following to split the one large partition into as many as you need:
http://www.majorgeeks.com/EASEUS_Partition_Master_Home_Edition_d5967.html

 

Are you wanting to duel boot with Windows and Ubuntu? With having an 80 GB HDD that is plenty of space to do it.
Though I agree with abekl that easus is a good choice, Parted Magic is also a really great tool for setting up your HDD with multiple partitions.
Once you set your partitions, then you can install windows on the first partition and set up Ubuntu on another. Now with that being said, you will be then using Grub2 as your bootloader and will be presented with a Grub menu upon boot up that will let you select Windows or Ubuntu.

All the best,

Ian