Disc partionining

I use Partition Magic for this purpose. It never fails for me. For further studies, you might want to read disk partitioning in Wikipedia.

If you are considering Linux, then simply download one of the many free distributions available and create a CD or DVD with the image supplied. You can now use the CD to partition the drive. During the early stages of installation you will be prompted to partition the hard drive, at which point you can choose to manually partition or permit the installation to partition and format the drive for you. Simply select the option to use the whole drive and the installation process will do the rest. If you decide to revert to Windows afterwards then it would depend on which version you were installing. For Windows XP you would need to use the Linux disk again and select manual partitioning to remove the partitions, then restart the computer with the Windows XP disk to partition and format. Windows Vista will happily repartition a drive that is partitioned and formatted for Linux, so in this case you need only insert the disk and proceed with installation.