Microsoft KB Archive/74496

= MS-DOS Device Driver Names Cannot be Used as File Names =

Article ID: 74496

Article Last Modified on 5/12/2003

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APPLIES TO


 * Microsoft MS-DOS 2.11 Standard Edition
 * Microsoft MS-DOS 3.1
 * Microsoft MS-DOS 3.2 Standard Edition
 * Microsoft MS-DOS 3.21 Standard Edition
 * Microsoft MS-DOS 3.3 Standard Edition
 * Microsoft MS-DOS 3.3a
 * Microsoft MS-DOS 4.0 Standard Edition
 * Microsoft MS-DOS 4.01 Standard Edition
 * Microsoft MS-DOS 5.0 Standard Edition
 * Microsoft MS-DOS 5.0a
 * Microsoft MS-DOS 6.0 Standard Edition
 * Microsoft MS-DOS 6.2 Standard Edition
 * Microsoft MS-DOS 6.21 Standard Edition
 * Microsoft MS-DOS 6.22 Standard Edition

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This article was previously published under Q74496



SUMMARY
Microsoft MS-DOS reserves certain names for system device drivers. If you try to name a file using one of these names, you will receive the following error message:

Write Fault Error Writing Device 

Abort, Retry, Ignore, Fail?

The solution is to change the file name.



MORE INFORMATION
Below is a list of default device driver names.   Name    Function CON    Keyboard and display PRN    System list device, usually a parallel port AUX    Auxiliary device, usually a serial port CLOCK$ System real-time clock NUL    Bit-bucket device A:-Z:  Drive letters COM1   First serial communications port LPT1   First parallel printer port LPT2   Second parallel printer port LPT3   Third parallel printer port COM2   Second serial communications port COM3   Third serial communications port COM4   Fourth serial communications port To identify system device driver names, use one of the following two commands:


 * mem /d | more
 * debug d 0070:0000

Additional query words: 6.22 2.x 3.x 4.x 5.00 5.00a 6.00 6.20

Keywords: KB74496

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