Microsoft KB Archive/126958

Automap Road Atlas: Unable to Read

PSS ID Number: Q126958 Article last modified on 12-15-1995

3.00 | 3.00

MS-DOS WINDOWS

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========================================================= 3.00 | 3.00 WINDOWS | MS-DOS kbhw kb3rdparty kbenv kberrmsg

= SYMPTOMS =

If you attempt to run the Setup program for Microsoft Automap Road Atlas and receive a disk read error for the disk drive, there may be a problem with the disk. It is also possible that the disk drive you are using to install Automap Road Atlas does not closely match the alignment of the machine that produced the disk.

During installation, you may receive one of the following error messages

unable to read

-or- unable to read from drive 

-or- unable to expand file:

where is the file you are trying to read or expand, and  is your drive (for example, A).

= CAUSE =

These error messages may result from a defective set of disks, from a bad disk, or a problem with the disk drive used during installation.

Disk read errors are almost always caused by such problems, rather than by problems related to memory configuration, usage, or other environmental factors.

= RESOLUTION =

You can perform a simple test to determine whether or not the drive is capable of reading the disk. (For more information about the MS- DOS COPY, SCANDISK, and CHKDSK commands, see the “More Information” section of this article.)

  Insert the first Setup disk.   Change to the disk drive you are using to install Automap Road Atlas, and type the following at the MS-DOS command prompt and press ENTER: copy . nul Repeat this step for each disk. NOTE: The COPY command opens, reads, and closes each file in the current directory. This test verifies that each file can actually be read from the disk. The MS-DOS XCOPY command cannot be used with NUL as the target.   At the MS-DOS command prompt, type the following and press ENTER: scandisk NOTE: The SCANDISK command is available on systems running Microsoft MS-DOS version 6.2, 6.21, and 6.22. SCANDISK cannot find or correct errors on CD-ROM drives.   At the MS-DOS command prompt, type the following and press ENTER: chkdsk 

If you encounter any read errors in the above tests, or if SCANDISK or CHKDSK report serious errors, perform the same tests on another computer. If several other computers are available, it may be advantageous to try more than one.

If the disks can be successfully read by another computer, first try to clean the disk heads, as advised by the computer manufacturer, and then retry the installation. If the installation still fails on this computer, there may be a problem with the disk drive. If no available computer can read the disks, it is likely the disk(s) are damaged.

= MORE INFORMATION =

COPY
Using the MS-DOS NUL device as the target for the COPY command is convenient because no file is created. The output of the command is discarded into what is called a bit-bucket. If you use NULL as the target filename by mistake, the command tries to create a file on the disk; this usually results in an error due to lack of disk space.

SCANDISK
SCANDISK checks and corrects problems in the following areas of each drive:


 * File allocation table (FAT)
 * File system structure (lost clusters, crosslinked files)
 * Directory tree structure
 * Physical surface of the drive (bad clusters)

Types of drives SCANDISK can find and correct errors on:


 * Hard drives
 * DriveSpace drives
 * DoubleSpace drives (if DoubleSpace is installed)
 * Floppy disk drives
 * RAM drives
 * Memory cards

CHKDSK
CHKDSK checks the status of a disk and displays a status report. CHKDSK can also correct disk errors.

The status report shows errors found in the MS-DOS File system, which consists of the File Allocation Table (FAT) and directories. CHKDSK also displays a summary of disk usage. (CHKDSK does not verify that the information in your files can be accurately read.) If errors exist on the disk, CHKDSK alerts you with a message.

For more information about how to perform this task in Windows, see your Windows printed documentation or online Help.

KBCategory: kbhw kb3rdparty kbenv kberrmsg KBSubcategory: win31

Additional reference words: kbhowto auto auto-map automap reference null scrap scratch ====================================================================== Keywords : win31 Version : 3.00 | 3.00 Platform : MS-DOS WINDOWS ============================================================================= Copyright Microsoft Corporation 1995.