Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!wuarchive!psuvax1!rutgers!bobsbox!graphics!elund From: elund@graphics.rent.com (Eric W. Lund - Subop) Newsgroups: comp.sys.ibm.pc.misc Subject: Re: CHKDSK --> "Probable non-DOS disk." Keywords: chkdsk disk DOS FAT Message-ID: Date: 11 Apr 91 05:45:43 GMT References: <1991Apr10.173621.26608@ux1.cso.uiuc.edu> Organization: The Graphics BBS (2D,3D,GIF,Animation) +1 908/469-0049 Lines: 20 dslg0849@uxa.cso.uiuc.edu (Daniel S. Lewart) writes: > Recently, when I 'chkdsk' my hard disk, I get the following error message: > c:\> chkdsk > Volume BIG_BLACK created Jan 1, 1991 12:00a > Probable non-DOS disk. > Continue (Y/N)? > If I type 'y', it continues and everything works fine. The DOS manual claims > the FAT ID byte is bad and that the disk has become 'badly damaged'. In fact > the disk seems to be functioning perfectly well. > > Is there any way I can fix this problem besides reformatting the disk? Something has partly trashed your FAT. The first byte in the FAT should be hex F8. The first byte is the "media descriptor byte", and F8 is for "fixed disks". To stop the message, use a sector editor and change the first byte back to what it should be. If your system is working fine now, then I wouldn't worry about it, but you should realize something has altered your FAT, and that's not a healthy thing for a program to do. The FAT should never be touched except by programs such as FDISK or FORMAT.