There are two main ways to unpartition your hard drive: manually or with automated partitioning software. The traditional method is to use a Microsoft DOS diskette to manually unpartition and repartition the drive, though this wipes out all data. The other method is to use third party software that can preserve your data. Both methods have pros and cons, but the latter method is easier for less adept computer users and has become increasingly popular, even among computer "geeks."

The traditional method requires a boot disk: a diskette with MS DOS system files. This boots your computer to a file system separate from the one located on your hard drive, allowing you to operate off the diskette to unpartition your drive. Since many computers no longer have a diskette drive, but are able to boot from a Universal Serial Bus (USB) device, the DOS files can be located on a memory stick that has been created as a bootable device. They can also be on an external drive, CD, or any other device that is bootable and is not part of the hard drive you wish to unpartition.

Once booted to a DOS prompt, the FDISK command is used to access the partition map on the drive. From here one can select a partition to delete, then repartition the drive as desired. This method is recommended if you want to unpartition the entire disk, then repartition it. This can be a good time to reformat the drive, though current operating systems offer the option of formatting the drive prior to installation.

Advantages to using the traditional DOS method to unpartition a drive are that it is free and some people prefer to do things manually for reliability reasons. This doesn’t follow if you don’t have much experience working with DOS or the FDISK command. The disadvantages are that the options are extremely limited and all data is lost in the unpartitioned portion of the drive. In most cases this means reinstalling the entire operating system and all programs, as typical drives have one active partition which contains an extended partition that holds all of the logical drives. When you unpartition the drive then, you wipe out all data.

A far easier, and perhaps more failsafe method to unpartition the drive, is to use a software program such as Norton Partition Magic or Acronis Disk Director Suite. These programs allow one to easily unpartition and repartition a drive while saving the data. These programs open inside the main operating system, eliminating the need to boot into DOS. Once the user chooses how he or she wants to unpartition the drive, the program takes over.

Automated software has many advantages: it is easier, faster, more flexible with many more options, and retains programs and files. Disadvantages are that the software is shareware (after the trial period, payment is required to keep using the software), and a small percentage of people report problems. Bugs and inconsistencies in operating systems have likely contributed in some cases, but ongoing improvements and fixes are standard operating procedure for every active software program, and most users experience no problems.

In the end, using automated software to unpartition a drive should make the task quick and painless. It is especially handy for combining or redistributing hard disk space among logical drives.