Writing to a read-only system file?

"Ben Myers" wrote in
:

TweakUI may have been the culprit. Some of its functions
require modification of the "c:\msdos.sys" file, so it
disregards the attributes. The version I am using is
somewhat cryptic in this particular item, displaying it
innocently under the "Boot" tab as "Start GUI automatically".
If this is unchecked, the computer will boot to a C:\ prompt,
without even telling the user how to start Windows or
reverse the change.

Ben

"ms" wrote in message
...
I recently had a machine where bootup stopped at a C prompt because
of

this.

The msdos.sys file is hidden, the attribute is read-only. Yet a sound
card
install apparently changed the default BootGUI setting from 1 to 0.

Changing it back restored the system.

How can any program write to a read only hidden file?

ms



Ben, that could well be it, I always use Tweakui, likely would have
checked that.

ms

"Ben Myers" wrote in
:

TweakUI may have been the culprit. Some of its functions
require modification of the "c:\msdos.sys" file, so it
disregards the attributes. The version I am using is
somewhat cryptic in this particular item, displaying it
innocently under the "Boot" tab as "Start GUI automatically".
If this is unchecked, the computer will boot to a C:\ prompt,
without even telling the user how to start Windows or
reverse the change.

Ben

"ms" wrote in message
...
I recently had a machine where bootup stopped at a C prompt because
of

this.

The msdos.sys file is hidden, the attribute is read-only. Yet a sound
card
install apparently changed the default BootGUI setting from 1 to 0.

Changing it back restored the system.

How can any program write to a read only hidden file?

ms


I checked, and "Start GUI automatically" had been left checked, so the
sound card, as Brian mentioned, must have been it. Still, I saved your
info as I always use Tweakui.

ms

"Brian A" gonefish'n@afarawaylake wrote in
:

Since now I see that you mention it was a Creative SB card, you may
have come on to
an unknown fix or only a temporary fix. It may present the problem
again, SB cards installed DOS emulation drivers so that sound could be
used in DOS and sometimes the problem would happen off the bat or
later down the road.

The fix/workaround for it was to disable the Creative SB 16bit
emulation or
whatever it was named in Device Manager. It's not installed in Sound,
video and game controllers, it's installed as one of the devices
listed at the top which I can't recall the name at this time.

If you're not going to be using sound in DOS, disable it and be done
with it.


Thanks, Brian, just as you said. In DM there were 2 listings for the
Soundblaster, one was "Legacy", I looked in details and it was 16 bit DOS
emulation. I disabled it.

ms

More likely, something went wrong and aborted the procedure that would have
changed the value back to normal.

--

Gary S. Terhune
MS-MVP Shell/User
http://grystmill.org/articles/cleanboot.htm
http://grystmill.org/articles/security.htm

"Hugh Candlin" wrote in message
...

"ms" wrote in message
...
"dadiOH" wrote in news:#LKS5LGGHHA.1216
@TK2MSFTNGP05.phx.gbl:

ms wrote:
I recently had a machine where bootup stopped at a C prompt because
of this.

The msdos.sys file is hidden, the attribute is read-only. Yet a
sound card install apparently changed the default BootGUI setting
from 1 to 0.

Changing it back restored the system.

How can any program write to a read only hidden file?

It is only "hidden" from you. It is "read only" only when writing to
it via the system. One can access files totally bypassing the system.
You think viruses use the system??

One can also, as Candlin said, change the attribute, write then
reinstitute the attribute. You can do that too via Windows.

BTW, not a good idea to have hidden files.

Thanks.

I didn't think Creative Soundblaster driver software (from it's own site)
would be written to do that. Windows booting to only a DOS prompt is not
normal, and that's the change it made.

ms

It is entirely possible that the Creative install modified your file
to force a reboot into DOS to replace one or more DLL library files
with newer versions as part of the install, which it could not do
while Windows was running and has control of those files.

It is also possible that the developer forgot to include code
to change the attributes back again after the installation was completed.

You could email Creative Support and ask them.