Fix drive letters - Slobodan?

[DPM]

We're trying to implement a procedure detailed by Slobodan for fixing drive
letters. The first two steps of his procedure are:
1. On target device, from a full build of Windows XP, export the following
keys to a REG file:
HKLM\System\MountedDevices
2. In Target Designer use file->import option to load registry values from
that REG file. Those keys will appear in the center pane in the "Extra
Registry Data" node.

We did step 1 and imported the REG file. What we cannot find is where the
"Extra Registry Data" node is. It does not appear in the center-pane
component list, at least not by that name. Where else would we look?
Please help!

 

[DPM]

I figured out where the "Extra Registry Data" was - what the procedure
failed to mention was that in TD "View" one needs to enable "Resources".

The real problem is that it doesn't work, or at least not the way I
expected. Here's the issue: my target only has one drive in it normally -
C:. If I plug a USB flash drive in after it boots, I'd expect it to be
assigned to D:, and that's what usually happens. But I have one USB drive
that ALWAYS gets assigned to E:. Same brand & size as three other drives -
yet this one appears as E:. I assumed that if I plugged a USB drive on a
target running XPpro, captured the registry key for it, imported that key
and changed it to D: in TD, then all USB flash drives would get assigned to
D:, but this does not appear to be the case.

So, the $64 question is: what's different about this particular drive that
makes XPe skip D: and assign E:? Why didn't the registry key work, or did I
misunderstand what it's supposed to do?

Thanks,
Dean

 

[Slobodan Brcin \(eMVP\)]

Hi Dean,

Basicaly fixed disks with valid MBR use following structure for defining and storing volume letter:
\DosDevices\G: - Represent that this partition will have G: volume letter assigned.
12 bytes (4+8) after it represent:
4 bytes Disk ID written in MBR that must be different for each disk used by XP OS.
8 bytes sector number that tell where partition start on disk.

In case of removable device this identifier is much complicated then simple 12 bytes and I never analyzed it, but what can you do
is to use regedit on XPe system and check MountedDevices for values written there by PnP and see if numbers for E: differ from ones
defined in TD.


Regards,
Slobodan

 

[Antoine Leca]

Bon dia,

In Slobodan Brcin va escriure:

12 bytes (4+8) after it represent: 4 bytes Disk ID written in MBR
that must be different for each disk used by XP OS.
8 bytes sector number that tell where partition start on disk.

My observations so far led to conclusion it is the _byte_ position on disk
instead. So if you have 512-byte sectors, you have to multiply by 512 the
(0-based LBA) sector number.


Hope it helps.

Antoine