repartition

http://www.help2go.com/Tutorials/Computer_Basics/How_to_Repartition_Hard_Drive_without_Reformatting.html

 

It uses a Linux live CD to boot your computer and prepare for a Linux installation. Don’t worry; you are not actually going to install Linux. Every Linux CD includes a program to resize your Windows partition to make room for Linux because Windows usually takes up the whole hard drive. Once we create the space for Linux, we can actually format it as a Windows partition, either NTFS or FAT32.

First, you need to download the Linux live CD. I recommend Simply MEPIS 3.3, available here: http://iso.linuxquestions.org/distro.php?distro=11 . These directions will assume you are using Simply MEPIS. Download the ISO and burn it to a CD as an ISO image. Check your CD burning software for info on burning an ISO. Once you have your CD, you are ready to begin.

Before you start- it is recommended to do a disk clean up, get rid of unnecessary files and defragment your hard drive to create as much continuous free space as possible. If your drive is very fragmented, you may want to defragment twice.