Using the FDISK Utility in Windows XP
FDISK is a software utility that prepares a hard drive for use by the computer. FDISK creates DOS partitions or removes partitions on a hard drive. Once a hard drive has a partition, it can be formatted so that it can hold files.
Partition and file system information
A hard drive partition is a definition of usable space. Once the data in the partition is formatted, an operating system (like DOS and Windows) can read and write files to it.
The first partition on a hard drive is called the primary partition. The second DOS partition is called the extended partition and is used to hold the second, and all other partitions on the drive. All partitions that are created in the extended partition are created as logical drives. Multiple partitions and other storage devices are separated by using drive letters. For example, the first partition of a hard drive exists as drive C, the first logical drive in the extended partition exists as drive D, and a CD-ROM might be drive E. Typically, C is the first letter that gets used for the primary partition. The number of partitions you can have on all of the hard drives on a computer is limited by the number of available letters. Since 26 letters are in the alphabet and some letters are already reserved for floppy, CD, DVD, Zip, and other drives, the remaining amount of letters are available for hard drive partitions.
Files are stored and written to drives by using a file system. The file system gets created when a hard drive is partitioned and formatted. Early versions of Windows and DOS use a FAT16 file system, using 32 kilobyte clusters of data and limits the size of partitions to two gigabytes. A FAT32 file system is used when formatting DOS partitions with Windows 95 OSR2, 98, or Me. FAT32 saves space and allows partition sizes of up to two terabytes (2,000 gigabytes), but cannot handle files that are greater than 4 GB. Windows NT, 2000, XP or later can use the New Technology File System (NTFS). NTFS partitions contain a lot of extra features like virtually unlimited file sizes, security, encryption, recoverability, and like FAT32, can be partitioned up to two terabytes.
Examples of hard drive configurations and partitions
- One hard drive with one active primary partition: This is probably the most common configuration and is recommended for normal use. Windows displays one drive, usually C, containing all available space in one partition.
- One hard drive with two partitions: Windows displays two drives, usually C and D. The first partition contains enough space for the operating system that it uses while the second partition, an extended partition with one logical drive, contains the remaining space for data storage.
- Two hard drives with one partition each: This is becoming more and more common as people upgrade their computers by adding a second hard drive. Both hard drives are partitioned with one primary partition. Windows displays two drives usually C and D, each with one partition using the full capacity of each drive.
Rules and limitations for partitioning a hard drive
The following items need to be considered before working with FDISK:
- The minimum partition size is one megabyte (MB).
- The maximum size for a partition on DOS 4.01 and earlier is 32 megabytes.
- The maximum size for a partition on DOS 5 through 6, and Windows 95 OSR1 is two gigabytes using the fat16 file system.
- The maximum size for a partition on DOS 7, and Windows 95 OSR2, 98, and Me, is two terabytes using the FAT32 file system.
- NTFS is classified as a non-DOS file system and is not created with FDISK. NTFS is created through a Windows operating system that is based on NT (like Windows 2000 and XP).
Before using FDISK
Before you can use FDISK, the hard drive must be jumpered correctly, as per the manufacturers instructions, so that the hard drive appears in BIOS Setup. Use the following steps to make sure that the drive appears in the BIOS Setup:
- Turn on the computer.
- Press the F1 key repeatedly when the first screen appears.
- Look at the information for primary IDE on the general screen:
- If the drive name appears for the proper IDE channel, FDISK can be used.
- If the drive does not appear for the IDE channel that it is on, something is wrong and needs to be corrected before you can use FDISK. Check the jumper on the hard drive and make sure that the IDE cable is plugged into the motherboard and into the back of the hard drive.
- Exit the BIOS when done.
FDISK.EXE needs to open just after the computer starts. Use one of the following methods to start FDISK:
- If the computer uses Windows 98, or Me, restart the computer in MS-DOS mode and type FDISK at the command prompt.
- Create a Startup disk on a Windows 98 or Me computer and then use it to start a computer with any version of Windows:
- Insert a write-enabled 3.5 disk into the floppy drive.
- Click Start, Settings, then Control Panel.
- Double-click Add/Remove Programs.
- Click the Startup Disk tab.
- Follow the instructions to create the disk.
- The Startup disk is bootable and contains FDISK.EXE. Put the disk in the computer that you want to use FDISK and start the computer.
- Type FDISK at the command prompt.
- If your computer came with recovery discs, use the first disc to open FDISK from a command prompt:
- Start the computer with the first recovery disc in the drive.
- The computer eventually opens with a recovery screen.
- Click Exit to DOS (or Command Prompt) from Advanced options.
- Type FDISK at the command prompt.
Follow these steps to use FDISK to delete, create, or view partitions:
- After starting FDISK, the first screen appears about enabling large disk support. Press the Y key and press the Enter key.
- The following choices appear at the FDISK options screen:
- Press the number key that corresponds to the action that you want to do. Use one of the sections that follow to find more information on each action.
- When you have finished preparing the hard disk(s), press the Esc key to exit FDISK and restart the computer.NOTE: New partitions require formatting before use. To format, type FORMAT X: (where X is the letter of the drive/partition) at a command prompt.
Creating a DOS partition or logical drive
Partitions and logical drives are created to allocate space on the hard drive for use by the operating system. In Windows, after the hard drive is set up, each partition will show up as hard drive complete with its own drive letter and an amount of usable space. Use the following steps to add a partition:
- At the FDISK Options screen, press the 1 key, and then press Enter.
- The following options appear:
- 1. Create Primary DOS Partition
- 2. Create Extended DOS partition
- 3. Create Logical DOS drive(s) in the Extended DOS Partition
- Type the number that corresponds to the type of partition that you want to create and press Enter. Keep the following items in mind when creating partitions:
- If there is no partition on the hard drive, create the first partition as a primary DOS partition. This does not apply if you want NTFS. If you want NTFS, leave the hard drive with no partitions and use the Windows NT/2000/XP setup disc to create the partition and format the drive.
- Create an extended partition before creating a logical DOS drive.
- A message appears about using the maximum available size after the drive integrity is checked. Do the following depending on how you want to configure the partitions:
- If you want to create the partition using all of the remaining space on the drive, press the Y key and then the Enter key.
- If you want more than one partition in this hard drive space, press the N key, the Enter key, and type the percentage or amount of disk space you want (for example, 40%, 50000). The integrity of the drive is verified again and the partition is created if the hard drive is good.
- If you are creating logical DOS drives in the extended partition, continue creating drives with the space that you want for each one until all of the space in the extended partition is used.
- After the partitions are made, press the Esc key to return to the FDISK options screen.
Setting the active partition
A hard drive has to contain one active partition before a drive can be started in the computers startup sequence. Usually, this is the primary partition. If you want to make the primary partition active, use the following steps:
- At the FDISK Options screen, press the 2 key, and then press Enter.
- Type the number for the primary partition that you want to make active (usually one), and then press Enter.
- Press Esc to return to the FDISK options screen.
Deleting a partition or logical drive
Deleting a partition or logical drive removes the definitions that tell the operating system about a given space on the hard drive. Deleting a partition or logical drive destroys the ability to read any data stored in that given space. Use the following steps to delete partitions.
CAUTION: Using FDISK to delete partitions on computers that come with a hidden recovery partition can destroy the system recovery application on the hard drive!
- At the FDISK Options screen, type 3, and then press Enter. The following options appear:
- 1. Delete Primary DOS Partition
- 2. Delete Extended DOS Partition
- 3. Delete Logical DOS Drive(s) in the Extended DOS Partition
- 4. Delete Non-DOS Partition
- Type the number that corresponds to the type of partition or logical drive that you want to delete and press Enter.NOTE: You have to delete all of the logical DOS drives inside of an extended partition before an extended partition can be deleted.
- Type the drive letter to delete (as shown in the information area on the display screen), then press Enter.CAUTION: If you have files on the computer that you want to keep, make sure that you are on the correct drive or partition before you continue. All data in the deleted partition or logical drive will be destroyed!
- Type the volume label exactly as shown on the displayed Partition information at the top of the screen, then press Enter. If there is no label, press Enter.
- Are you sure? (Y/N) is displayed. Press the Y key, and then press Enter to delete the partition and any information stored within.
- Press the Esc key to return to the FDISK options screen.
Displaying partition information
Using FDISK incorrectly can destroy a lot of valuable information very quickly. It is important that you have the right information when working with partitions. Use the following steps to view drive information:
- At the FDISK Options screen, press the 4 key, and then press Enter.
- The following are items that are listed and their meaning:
- Partition: This shows the drive letter that is currently assigned to the partition and a corresponding number. Drive letters do not appear for extended partitions and non-DOS partition.
- Status: The letter A is shown if the partition is set as active. Otherwise, nothing is displayed.
- Type: The shortened words underneath represent the type of partition. For example, PRI DOS equals primary DOS and EXT DOS stands for extended DOS partition.
- Volume Label: This is a short label that can be assigned to the partition when it is created. It can also be changed through Windows in the drive’s label field inside its Properties window. It is acceptable to leave the volume label blank.
- Mbytes: The volume of the partition in megabytes.
- System: If the partition has been formatted, then the type of formatting is shown (FAT16, FAT32, NON DOS).
- Usage: The percentage of the entire drive that is being used by the partition.
- Press Esc to return to the FDISK options screen.
Changing to a different hard drive
When working in FDISK with more than one hard drive, it is important to work with the correct drive. Use the following steps to change to the hard drive that needs partition work:
- At the FDISK Options screen, press the 5 key, and then press Enter.The drive information appears at the top of the screen.
- Type the number of the drive that you want to change to, and then press Enter.
Using FDISK to clear the boot sector (erase boot sector viruses)
The boot sector of a hard drive contains the hard drive's startup information and holds the partition information. If the boot sector of a hard drive is corrupt or becomes infected by a boot sector virus, the drive will stop functioning or cause damage to the files stored on the drive. To try and restore the boot sector, type FDISK/MBR at a command prompt. FDISK rewrites the boot sector code while leaving the partition tables intact. This parameter should only be used if a problem is suspected and may not erase some boot sector viruses.