KB127852 - Total Free Space Reported Incorrectly on Drives Larger Than 2 GB

Article ID: 127852

Article Last Modified on 11/15/2006

Microsoft Windows 95

This article was previously published under Q127852

SYMPTOMS

When you are using Windows 95 to access a mapped network drive that is larger than 2 gigabytes (GB) in size (for example, an NTFS or FAT volume shared by a Windows NT server), Windows 95 reports only 2 GB of disk space for the network drive.

If the network drive is larger than 2 GB and has more than 2 GB of available disk space, Windows 95 reports 2 GB of total disk space, 2 GB of available disk space, and 0 bytes of used disk space. If the network drive has less than 2 GB of available disk space, Windows 95 reports the available disk space correctly.

If you use Windows 95 OEM Service Release 2 (OSR2) with a local hard disk that uses the FAT32 file system, Windows reports 0 bytes of used space if the hard disk has more than 2 GB of available disk space. If the local hard disk has less than 2 GB of available disk space, Windows reports the available disk space correctly.

RESOLUTION

To work around this behavior for a local hard disk that uses the FAT32 file system, install Microsoft Internet Explorer 4.0 with the Windows Desktop Update component. Note that this method does not work around this behavior with network drives.

For information about obtaining Internet Explorer 4.0, visit the following Microsoft Web site:

http://www.microsoft.com/ie/

STATUS

This behavior is by design for network drives.

MORE INFORMATION

Both Microsoft MS-DOS and Windows 95 use a 16-bit FAT for logical drives larger than 15 megabytes (MB). The maximum number of clusters for a 16-bit FAT drive is 64K, or 65,536 bytes (where 1K = 1024 bytes). In addition, the maximum cluster size in MS-DOS and Windows 95 is 32K, or 32,768 bytes. Based on this information, the maximum logical drive size in MS-DOS and Windows 95 is calculated as follows:

   32K x 64K = 2048 MB = 2 GB

Note that when you connect to a network share using a UNC connection and you check the properties of a folder on the network share, Windows 95 (retail and OEM Service Release 2) accurately reports its size up to 4 GB. If the network share's size exceeds 4 GB, the properties for the folder show the byte counter properly incrementing up to 4 GB, and then the counter resets back to 0 and resumes counting. For example, with a 4.5-GB share, the counter counts up to 4 GB, starts over at 0, and then continues incrementing up to 500 MB.

To maintain compatibility with MS-DOS-based and Windows-based programs that assume a 2-GB drive size limit, the Windows 95 network redirector (Vredir.vxd) never reports more than 2 GB of total or available disk space on network drives.

Additional query words: 1.99 large partition

Keywords: kb3rdparty kbdiskmemory kbnetwork KB127852