Boot-time drive letter assignment...

[RatPack]

Win XP Home SP2

I'm trying to establish at what point in the boot sequence drive letters are assigned.

I understand that once NTLDR has selected from which active Primary partition to load the OS, and provided F8 has not been depressed, NTDETECT.COM is loaded and hardware detection occurs.

Following hardware detection, and provided a Hardware Profile does not have to be selected, NTLDR begins the loading of the OS kernel (Ntoskrnl.exe).

So, are letters assigned by NTDETECT.Com or the OS kernel or later in the process. Or does NTDETECT.COM prepare a priority list of drives with C: allocated to the first active Primary partition which it encounters and hand the list to the boot sequence?

TIA.

[jaclaz]

Cannot answer your question, but as I see it this is not correct:

once NTLDR has selected from which active Primary partition to load the OS

There is NO need whatsoever for the partition to be Primary, nor Active, any NT based system can be as well installed on logical volumes inside Extended.

As far as I know all the booting happens using "internal" names, like arcpaths and \\Hardiskx\ syntax, drive lettering is only used later for some Registry settings, automatic lettering can be overridden by migrate.inf.

Check these for some info:

http://www.msfn.org/board/index.php?showtopic=85729&hl=

http://www.boot-land.net/forums/index.php?...ic=2425&hl=

http://www.911cd.net/forums//index.php?showtopic=19663

(and links therein)

jaclaz

[RatPack]

as I see it this is not correct:

once NTLDR has selected from which active Primary partition to load the OS

OK, I probably misinterpreted the following extract:

Partition Table The partition loader (or Boot Loader) examines the partition table for a partition marked as active. The partition loader then searches the very first sector of that partition for a Boot Record.

Seems like only a Boot Record has to be on an active partition.

Thanks for your interest.

[Ponch]

once NTLDR has selected from which active Primary partition to load the OS

There is NO need whatsoever for the partition to be Primary, nor Active, any NT based system can be as well installed on logical volumes inside Extended.

I'd say the NTLDR from the primary active partition is selected and then it points to the OS that can be installed on an other partition indeed.

[jaclaz]

Yep, you don't even need a Primary partition, you can boot from floppy or oter removable device (can also be used as a primitive but quite effective security measure if you do not want people fiddling with your PC):

http://www.xxcopy.com/xxcopy33.htm

jaclaz