How could I tell os which disk partition is C:

NTDEV
1

I have two partition on a disk and each partition has a win2k installed in it. When the system boot
which partition would be the C: disk

craiglei

2

At 02.40 20/05/2002, you wrote:

I have two partition on a disk and each partition has a win2k installed in
it. When the system boot
which partition would be the C: disk

On Windows NT 4 and earlier, the first partition of the first detected
fixed disk becomes C:. On NT 5 and later, partitions are identified with a
GUID (using native BIOS services on IA64, and emulating them by keeping
track of every partition’s offset and size and associating them with a GUID
on i386), that is a randomly generated 128-bit identifier, and a service
called Mount Manager maps them to drive letters for DOS and Win32. The
Mount Manager mappings are preserved across reboots, aren’t necessarily
influenced by the order of disks and partitions, and are entirely
configurable: for example, on my machine I don’t have a C: drive, letters
start from D:, and in exceptional cases I have even removed D:

3

On NT4 the first disk/partition needn’t be C: (or for there even to be a C: drive available). This is all tracked at:
HKLM\system\disk\information
And www.sysinternals.com has a few good articles about the information contained therein.

Regards,

Paul Bunn, UltraBac Software, 425-644-6000
Microsoft MVP - Windows NT/2000/XP
http://www.ultrabac.com

-----Original Message-----
From: KJK::Hyperion [mailto:xxxxx@libero.it]
Sent: Sunday, May 19, 2002 9:52 PM
To: NT Developers Interest List
Subject: [ntdev] Re: How could I tell os which disk partition is C:

At 02.40 20/05/2002, you wrote:

I have two partition on a disk and each partition has a win2k installed in
it. When the system boot
which partition would be the C: disk

On Windows NT 4 and earlier, the first partition of the first detected
fixed disk becomes C:. On NT 5 and later, partitions are identified with a
GUID (using native BIOS services on IA64, and emulating them by keeping
track of every partition’s offset and size and associating them with a GUID
on i386), that is a randomly generated 128-bit identifier, and a service
called Mount Manager maps them to drive letters for DOS and Win32. The
Mount Manager mappings are preserved across reboots, aren’t necessarily
influenced by the order of disks and partitions, and are entirely
configurable: for example, on my machine I don’t have a C: drive, letters
start from D:, and in exceptional cases I have even removed D:

4

> On Windows NT 4 and earlier, the first partition of the first detected

fixed disk becomes C:

IIRC NT4 uses the Disk registry key for drive letter mappings.
It will boot fine anyway, since only the \SystemRoot paths are used at boot. Then it will start SMSS, which will sooner or later
read the Disk key, initialize the drive letters and then proceed with the rest of initialization, but I suspect the WINDIR
environment variable will be used at the later stages too instead of explicit drive letter.

Max