Microsoft Anti-Virus CHKLIST.MS Files Explained (99148)



The information in this article applies to:
    Microsoft MS-DOS operating system 6.0
    Microsoft MS-DOS operating system 6.2
    Microsoft MS-DOS operating system 6.21
    Microsoft MS-DOS operating system 6.22

This article was previously published under Q99148

SUMMARY

Microsoft Anti-Virus for MS-DOS (MSAV.EXE) and Microsoft Anti-Virus for Windows (MWAV.EXE) create CHKLIST.MS files in most, if not all, of your directories.

MORE INFORMATION

CHKLIST.MS is a "checksum" file. A checksum is an error-detection scheme that involves creating a sum of the bits in a set of bytes of data and using that sum to later check for a change in the data. Checksums are commonly used in communications software to check for data transmission errors.

In the case of Microsoft Anti-Virus, the CHKLIST file contains checksums for certain files in the directory containing the CHKLIST file. The checksums are based on the data contained in each file. The checksum is stored along with each file's size, attributes, date, and time. This information is used by Microsoft Anti-Virus during the Detect phase to check for changes to the files in the directory.

The files are created (and updated) by Microsoft Anti-Virus during the Detect or Detect And Clean scanning process if the Create New Checksums option is selected in the Options dialog box.

Checksums are created for files with the following extensions:

386
APP
BIN
CMD
COM
DLL
DRV
EXE
FON
OV*
PGM
PRG
SYS

Deleting the CHKLIST.MS Files

The CHKLIST files can be deleted. To do this, press F7 in Microsoft Anti-Virus for MS-DOS or choose Delete CHKLIST Files from the Scan menu in Microsoft Anti-Virus for Windows.

If you disable the use of the CHKLIST.MS files, Microsoft Anti-Virus does not check for unexpected changes in files. (It can scan files for known virus signatures only.)

Modification Type: Major Last Reviewed: 2/20/2002
Keywords: KB99148