System Disk (C) changes from disk 0 to disk 1 in Disk Management

[Guest]

Hello:

I have always thought that the C drive system disk should be disk 0 in
Control Panel/Administrative Tools/Computer Management/Disk Managment. I
recently did a re-install of Windows XP Pro with only the C drive connected.
The install went OK and I then reinstalled all of my software. I did this
because one of my programs was revertng back to an expired 30 day trial and
after trying everything the company suggested I reinstall Windows. This
software that I paid $500 for reverts back to the expire trial if it thinks
the C drive serial number has changed. I have discovered that immediately
after I reinstalled XP the system disk C was disk 0. I turned off the
computer, opened the case and reconnected my second hard drive "D" and
restarted the machine. I then plugged in my two Firewire 800 external
drives. I went into Disk Management and the system disk (C) was still disk
0. Tonight when I tried to open the software mentioned above it reverted
back to the expired 30 day trial. I checked in Disk Management and the
system disk (C) is now showing as disk 1. There is no disk 0 listed. I am
sure that this is why my software is reverting back to the expired trial - it
thinks the C disk has changed.

Does anyone know why the system disk C is changing from disk 0 to disk 1?

Thanks!

Bill

 

[Ron Sommer]

What happened to D?
Are C and D IDE drives?
How are they jumpered?
What happens if you disconnect D?
What is the Bios showing?
--
Ronald Sommer

: Hello:
:
: I have always thought that the C drive system disk should be disk 0 in
: Control Panel/Administrative Tools/Computer Management/Disk Managment. I
: recently did a re-install of Windows XP Pro with only the C drive
connected.
: The install went OK and I then reinstalled all of my software. I did this
: because one of my programs was revertng back to an expired 30 day trial
and
: after trying everything the company suggested I reinstall Windows. This
: software that I paid $500 for reverts back to the expire trial if it
thinks
: the C drive serial number has changed. I have discovered that immediately
: after I reinstalled XP the system disk C was disk 0. I turned off the
: computer, opened the case and reconnected my second hard drive "D" and
: restarted the machine. I then plugged in my two Firewire 800 external
: drives. I went into Disk Management and the system disk (C) was still
disk
: 0. Tonight when I tried to open the software mentioned above it reverted
: back to the expired 30 day trial. I checked in Disk Management and the
: system disk (C) is now showing as disk 1. There is no disk 0 listed. I
am
: sure that this is why my software is reverting back to the expired trial -
it
: thinks the C disk has changed.
:
: Does anyone know why the system disk C is changing from disk 0 to disk 1?
:
: Thanks!
:
: Bill
:
:
:
: --
: Regards,
:
: Bill Artman

 

[Edwin vMierlo]

First of all, it should not matter if your C drive is 0 or 1
If it does for some software then I would call that crappy software (with
all respect, but physical drive numbering is volatile and could change upon
reboot or introduction of hardware)

So now to your second point, why does it change ?

Well, when the OS boots, PnP will ask the bus-drivers to "walk the bus" and
report back all devices it sees. Then an "object" is created for each device
in the sequence it is reported.

So the first drive reported will get number 0, the second reported will get
number 1 and so on.

The sequence can change when you have added hardware to your system which is
reported before your original disk (this is the driver reporting to PnP upon
boot time !!!)
And the sequence can change when you upgrade a driver (again the driver is
reporting it to PnP, so whoever is writing the driver can change the
sequence and therefore influence the numbering !!)

This probably doesn't really answer your question, but I hope this will help
you understand physicaldrive numbering.

HTH,
_Edwin.

 

[Ron Sommer]

I don't have a clue for how to fix your problem.
Disk 0 is what the Bios uses as the first disk in the hard drive boot order.
C is the first active partition.
C doesn't have to on disk 0.
--
Ronald Sommer

:
: Ron;
:
: I have 4 Maxtor drives connected to my XP Pro machine.
:
: In Computer Management - Disk Management:
:
: C (system) is an IDE and shows as disk 1
:
: D shows is an IDE and shows as disk 2
:
: G an external Firewire disk shows as disk 3
:
: H an external Firewire disk shows as disk 4
:
: There is no disk 0 as I think there should be.
:
: Drives E and F are CD/DVD drives.
:
: The C drive is jumpered as Master and the D drive is jumper as Slave.
:
: When you disconnect D and the two external drives and reboot the machine
the
: system C drive shows disk 0 (like I think it always should regardless).
:
: The Bios shows the C drive as the primary boot drive and D as the
secondary
: drive.
:
: I have two other XP machines with both a C and D drive, In Computer
: Management - Disk Management the system C drive always shows disk 0 and
the D
: drive always shows disk 1.
:
: I always thought that Windows looks at the system disk (C) which has the
: operating system as disk 0.
:
: Do you have any thoughts? Thanks very much!
:
:
:
:
:
: --
: Regards,
:
: Bill Artman
:
:
: "Ron Sommer" wrote:
:
: > What happened to D?
: > Are C and D IDE drives?
: > How are they jumpered?
: > What happens if you disconnect D?
: > What is the Bios showing?
: > --
: > Ronald Sommer
: >
: > : > : Hello:
: > :
: > : I have always thought that the C drive system disk should be disk 0 in
: > : Control Panel/Administrative Tools/Computer Management/Disk Managment.
I
: > : recently did a re-install of Windows XP Pro with only the C drive
: > connected.
: > : The install went OK and I then reinstalled all of my software. I did
this
: > : because one of my programs was revertng back to an expired 30 day
trial
: > and
: > : after trying everything the company suggested I reinstall Windows.
This
: > : software that I paid $500 for reverts back to the expire trial if it
: > thinks
: > : the C drive serial number has changed. I have discovered that
immediately
: > : after I reinstalled XP the system disk C was disk 0. I turned off the
: > : computer, opened the case and reconnected my second hard drive "D" and
: > : restarted the machine. I then plugged in my two Firewire 800 external
: > : drives. I went into Disk Management and the system disk (C) was still
: > disk
: > : 0. Tonight when I tried to open the software mentioned above it
reverted
: > : back to the expired 30 day trial. I checked in Disk Management and
the
: > : system disk (C) is now showing as disk 1. There is no disk 0 listed.
I
: > am
: > : sure that this is why my software is reverting back to the expired
trial -
: > it
: > : thinks the C disk has changed.
: > :
: > : Does anyone know why the system disk C is changing from disk 0 to disk
1?
: > :
: > : Thanks!
: > :
: > : Bill
: > :
: > :
: > :
: > : --
: > : Regards,
: > :
: > : Bill Artman
: >
: >