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Size of Disk Drive Does Not Match Specifications (Windows 7, Vista)

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This document applies to HP computers with Windows 7 or Windows Vista operating system.
HP computers that come with Windows 7 or Windows Vista preinstalled appear to have a hard drive smaller than what is stated in the product specifications, documentation, or what is stated on the box. Windows appears to report a smaller hard drive capacity because it shows information about one partition on the hard drive at a time and there are two commonly used reporting systems for binary data.

Understanding hard drive partitions and space usage in Windows 7 and Vista computers

HP computers with Windows Vista have hard drives that contain two partitions. The first partition contains space that is usable. This partition is usually the C: drive and may be labeled HP or COMPAQ . The second partition contains system recovery information and is labeled RECOVERY or FACTORY_IMAGE .
HP computers with Windows 7 have hard drives that contain a third partition labeled SYSTEM . This partition is protected space used by Windows.
For more information on a given topic, click the heading or the accompanying plus (+) sign to expand the information.
Use System Information to view the total size of the hard drive. System information reports total space in both binary notation and in total bytes (decimal); these are two measures you can use to understand true disk space.
  1. Click Start , and enter msinfo32 into the Search field. Click msinfo32 .
    Figure 1: Search results for msinfo32
    Search results for msinfo32
    System Information opens.
  2. Click the plus sign (+ ) next to Components , under System Summary.
    Figure 2: Components selected in the System Information window
    Components selected in the System Information window
  3. Click the plus sign (+ ) next to Storage under Components.
    Figure 3: Storage selected in the System Information window
    Storage selected in the System Information window
  4. Select Disks under Storage.
    Figure 4: Disks selected in the System Information window
    Disks selected in the System Information window
  5. View the information that is provided. For example, total disk space and the two partitions on the hard disk drive are shown. The total disk size is 232.88 GB (gigabytes) as reported by Windows. This equals a little over 250 billion bytes in exact size when using decimal measurement. The hard drive shown is a typical 250 gigabyte hard drive.
    Figure 5: Hard Disk Drive Space shown for a Windows 7 computer
    Hard Disk Drive Space shown for a Windows 7 computer
    1 - Total hard disk drive space
    2 - Protected space used by Windows
    3 - Space for normal use within an operating system
    4 - Space reserved for a system recovery
    Figure 6: Hard Disk Drive Space shown for a Windows Vista computer
    Hard Disk Drive Space shown for a Windows Vista computer
    1 - Total hard disk drive space
    2 - Space for normal use within an operating system
    3 - Space reserved for a system recovery
Sometimes the total amount of disk space is not made available and a portion of the hard drive space is left as unallocated. This can happen if an additional hard drive is added and not partitioned correctly, or the factory-installed software image did not properly match the size of the hard drive.
If your hard drive contains a significant amount of unallocated space, use the following step-by-step process to add the unused space to the hard drive.
CAUTION: Do not use the RECOVERY or FACTORY_IMAGE partition! Doing so allocates the unused space to the system recovery partition which is used only to recover the computer.
CAUTION: Do not use the SYSTEM partition! Windows uses this partition to store important system files including startup recovery and system restore points.
  1. Click Start , right-click Computer , then click Manage .
    If you are prompted for an Administrator password or confirmation, type the password or provide confirmation.
  2. Double-click Storage , and then click Disk Management .
    Figure 7: Disk Management
    Disk Management
  3. You can view the amount of unallocated space on the drive from the Computer Management screen. Unallocated space appears in a section without a partition label and with a black bar at the top. Unallocated space is unused space on the hard drive that cannot be used.
    Figure 8: 250 GB disk drive showing with 11.72 GB of unallocated space
    250 GB disk drive showing with 11.72 GB of unallocated space
    NOTE:If Unallocated space is not listed for a Disk, the Disk is correctly allocated.
  4. From the Computer Management screen, right-click the hard drive volume that you want to extend (for this example, Disk 0 (C:) ), and select Extend Volume . Do not select the SYSTEM, RECOVERY, or FACTORY_IMAGE partition.
    Figure 9: Extend Volume selected in the Computer Management window
    Extend Volume selected in the Computer Management window
  5. Click Next when the Extend Volume Wizard opens.
  6. Select the Disk that you want to extend, set the amount of space to extend, and then click Next . To accept the maximum amount of available unallocated space, do not change any of the size values shown.
    Figure 10: Extend Volume Wizard
    Extend Volume Wizard
  7. Click Finish to complete.
  8. The previously unallocated space can now be used and the correct values for the drive capacities are now shown from the Computer Management Window.
    Figure 11: 250 GB disk drive with fully allocated space
    250 GB disk drive with fully  allocated space
Different software/hardware and vendors use different ways of measuring a gigabyte. What Windows displays as the size of a hard drive may be less than the actual size.

Definition of decimal hard drive size in Windows 7 and Vista computers

Hard drives are described and advertised by manufacturers in terms of decimal (or base 10) capacity. In decimal notation, one megabyte (MB) is equal to 1,000,000 bytes, and one gigabyte (GB) is equal to 1,000,000,000 bytes. The decimal system is what we are accustomed to in everyday life.

Definition of binary hard drive size in Windows 7 and Vista computers

Windows and other programs have reporting features that use the binary (or base 2) numbering system. In the binary numbering system, one megabyte is equal to 1,048,576 bytes, and one gigabyte is equal to 1,073,741,824 bytes.

Convert binary size to decimal size in Windows 7 and Vista computers

When determining hard drive capacity with software that reports in base 2 notation multiply the base 2 notation value by 1,048,576 to determine the decimal equivalent.
The information stored on the Recovery or Factory Image partition is important system information consisting of a backup of Windows and original factory-installed software.
For HP computers made prior to Windows Vista, recovery information was provided on disc(s). HP no longer includes recovery discs with most computers because:
  • Discs can become destroyed by scratches.
  • Discs can become lost.
  • Discs can fail after prolonged exposure to sunlight.
  • Discs add cost to the price of the computer.
  • Recovering from the hard drive is substantially faster than recovering from discs, and does not require disc swapping.
You should still create recovery discs using the Recovery software program provided by HP. For more information, see Obtaining a Recovery CD or DVD set .
The information stored on the System partition is used by Windows to store important system files including startup recovery and system restore points.