DOCUMENT:Q74589 17-DEC-2000 [msdos] TITLE :Hidden System Files and MS-DOS 5 and Later Upgrade PRODUCT :Microsoft Disk Operating System PROD/VER:MS-DOS:5.x,6.0,6.2,6.21,6.22 OPER/SYS: KEYWORDS: ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft MS-DOS operating system versions 5.0, 5.0a, 6.0, 6.2, 6.21, 6.22 ------------------------------------------------------------------------------- SUMMARY ======= The Microsoft MS-DOS Upgrade Setup copies the hidden system files IO.SYS and MSDOS.SYS to the front of the root directory in the boot drive. If the previous version of DOS had files called IO.SYS and MSDOS.SYS created by Microsoft, those files will be deleted. If the previous version of DOS has hidden system files by other names or that were not created by Microsoft, they are moved to the first available space in the root directory of the bootable hard drive. These files can then be deleted after resetting the file attributes. The following command will turn off the system file attribute, the hidden file attribute, and the read-only file attribute of a file named IBMBIO.COM. attrib -s -h -r ibmbio.com These files can also be deleted using MS-DOS Shell. Additional query words: 6.22 5.00 5.00a 6.00 6.20 ====================================================================== Keywords : Technology : kbMSDOSSearch kbMSDOS621 kbMSDOS622 kbMSDOS620 kbMSDOS600 kbMSDOS500 kbMSDOS500a Version : MS-DOS:5.x,6.0,6.2,6.21,6.22 ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2000.