I teach computer maintenance at a school and had a virus that spread around
the classroom that did just that same thing. After rebooting, FDISK showed
the primary DOS partition had been changed to a NON-DOS partition. You might
check for a virus on a boot floppy disk.
Bill Havard
----- Original Message -----
From: "Ian Porter" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, August 27, 2002 12:31 AM
Subject: [PCBUILD] Primary Dos partitions become Non-Dos - headache!


> Hi all.
>
> I have a recurrent problem which is driving me nuts - partitions on my own
> system that have been set up as Primary Dos frequently change themselves
to
> Non-Dos.
>
> I previously posted about this some months back, but I'll try again, just
in
> case anyone has fresh thoughts on the matter.
>
> My system is W98SE.  My hardware is irrelevant, I think, as this problem
has
> persisted throughout hardware changes, but the mobo is a recent model
> Gigabyte, with 512Mb DDR ram.  The drives are all UltraDMA 133, 7200 rpm.
> All were originally set up as Fat32.
>
> The 20 Gb single-partition system drive, C, is labelled Max20.
> Another single-partition drive, D, is used for storage, and is labelled
> Max40.
>
> These two are master and slave on IDE0.
>
> Max20's single partition was set up as a Primary Dos partition about 6
> months ago, but has since reverted to a Non-Dos partition.  I didn't
notice
> it at the time, but it probably occurred about 6-8 weeks back.
>
> Max40's single partition is Primary Dos.
>
> Yesterday I launched an attempt to restore Max20 to Pri-Dos status. This
is
> important to me because I make frequent excursions into DOS, and things
are
> a little awkward when the OS drive can't be seen in DOS.
>
> To help with the restoration, I employed another drive, Sam40, on IDE1, to
> be used as a temporary staging post.
>
> Here's the sequence of events:
>
> Using the NoSpin boot disk, I booted to DOS.
> I used FDisk and on Sam40 I deleted the existing single partition.  Next I
> created a single Primary Dos partition, then rebooted and formatted the
disk
> with the /s switch.
>
> I rebooted to Windows and copied the whole of Max20 to Sam40 using
> Drive2Drive. Then I shut down and reset the jumpers on all three drives to
> suit, changed the BIOS boot sequence and rebooted to Windows.  Sam40 had
> become the OS drive and Windows worked OK.
>
> Rebooted to DOS, checked status with FDisk.  Max40 was now reported as
> Non-Dos, it had somehow changed from Primary Dos!  Sam40 was still Primary
> Dos, Max20 was still Non-Dos, no change in the status of these two.
>
> Ran FDisk, reconfigured Max20 to Primary Dos and formatted it with /s.
>
> Rebooted to DOS and checked status.  Max20 is now Primary Dos.  But what
> the.....!  Max40 has gone back to Primary Dos, while Sam40 is now showing
up
> as Non-Dos.
>
> Here I paused to tear out my remaining hair, then went to bed.
>
> This morning I disconnected Max20 and Max40 completely, and rebooted into
> DOS with Sam40.  Again, I FDisked the drive, reconfiguring it to a single
> Primary Dos partition, then formatted it with the /s switch.
>
> Then I disconnected Sam40, reconnected Max20 and Max40 and rebooted to
DOS.
> Both have retained their single-partition status as Primary Dos.  Whew! So
> far so good.
>
> But the exercise created more questions than answers.  And I don't feel at
> all confident that any of these settings will endure.
>
> I know that the Pri-Dos\Non-Dos status configuration is locked into the
> setting of a just a few bytes on the hard drive, I presume somewhere in
the
> FAT.
>
> But because of the way that Max40 fluctuated un-assisted from Pri-Dos to
> Non-Dos then back to Pri-Dos, perhaps it's something that I can
manipulate?
>
> I've combed the net for information on the subject, but what little is
there
> refers only W95, and doesn't help.
>
> Constructive suggestions will be welcomed with glad cries.
>
> TIA
>
> Ian Porter
> Computer Guys Inc.
> Arrowtown
> New Zealand
> [log in to unmask]
>
>                          PCBUILD's List Owners:
>                       Bob Wright<[log in to unmask]>
>                        Drew Dunn<[log in to unmask]>
>

                  Visit our website regularly for FAQs,
               articles, how-to's, tech tips and much more
                          http://freepctech.com