BTW, I noticed that on W2000 when it is being debuggged (with debugging enabled) a COM port “disappears” from the list of devices because kernel debugger “ownes” it that point.
On Vista, when it is being debugged (with debugging enabled) a COM port is still visible in Device Manager. Maybe it is just the way it is on vista, but I thought it may provide some extra clues…
Just in case, here is the output of bcdedit /enum all: (I have added an entry “DebugEntry”)
Windows Boot Manager
identifier {bootmgr}
device partition=C:
description Windows Boot Manager
locale en-us
inherit {globalsettings}
default {current}
displayorder {current}
{c7e18f8d-97a1-11e0-a4d6-90e6ba320ad5}
toolsdisplayorder {memdiag}
timeout 30
resume No
customactions 0x1000085000001
0x54000001
custom:54000001 {863df33e-9817-11dc-b72e-001b24047e4e}
Windows Boot Loader
identifier {572bcd55-ffa7-11d9-aae0-0007e994107d}
device ramdisk=[D:]\sources\boot.wim,{ad6c7bc8-fa0f-11da-8ddf-0013200354d8}
path \windows\system32\boot\winload.exe
description HP Recovery Manager
osdevice ramdisk=[D:]\sources\boot.wim,{ad6c7bc8-fa0f-11da-8ddf-0013200354d8}
systemroot \windows
nx OptIn
detecthal Yes
winpe Yes
Windows Boot Loader
identifier {572bcd55-ffa7-11d9-aae2-0007e994107d}
device ramdisk=[D:]\sources\boot.wim,{ramdiskoptions}
path \windows\system32\boot\winload.exe
description HP Recovery Manager
osdevice ramdisk=[D:]\sources\boot.wim,{ramdiskoptions}
systemroot \windows
nx OptIn
detecthal Yes
winpe Yes
Windows Boot Loader
identifier {863df33e-9817-11dc-b72e-001b24047e4e}
device ramdisk=[D:]\sources\boot.wim,{ramdiskoptions}
path \windows\system32\boot\winload.exe
description F11 Boot from BCD
osdevice ramdisk=[D:]\sources\boot.wim,{ramdiskoptions}
systemroot \windows
nx OptIn
detecthal Yes
winpe Yes
Windows Boot Loader
identifier {current}
device partition=C:
path \Windows\system32\winload.exe
description Microsoft Windows Vista
locale en-us
inherit {bootloadersettings}
recoverysequence {572bcd55-ffa7-11d9-aae2-0007e994107d}
recoveryenabled Yes
osdevice partition=C:
systemroot \Windows
resumeobject {c5b62456-b827-11de-9bbe-90e6ba320ad5}
nx OptIn
debug Yes
Windows Boot Loader
identifier {c7e18f8d-97a1-11e0-a4d6-90e6ba320ad5}
device partition=C:
path \Windows\system32\winload.exe
description DebugEntry
locale en-us
inherit {bootloadersettings}
recoverysequence {572bcd55-ffa7-11d9-aae2-0007e994107d}
recoveryenabled Yes
osdevice partition=C:
systemroot \Windows
resumeobject {c5b62456-b827-11de-9bbe-90e6ba320ad5}
nx OptIn
debug Yes
Resume from Hibernate
identifier {c5b62456-b827-11de-9bbe-90e6ba320ad5}
device partition=C:
path \Windows\system32\winresume.exe
description Windows Resume Application
locale en-US
inherit {resumeloadersettings}
filedevice partition=C:
filepath \hiberfil.sys
debugoptionenabled Yes
Windows Memory Tester
identifier {memdiag}
device partition=C:
path \boot\memtest.exe
description Windows Memory Diagnostic
locale en-US
inherit {globalsettings}
badmemoryaccess Yes
Windows Legacy OS Loader
identifier {ntldr}
device partition=C:
path \ntldr
description Earlier Version of Windows
EMS Settings
identifier {emssettings}
bootems Yes
Debugger Settings
identifier {dbgsettings}
debugtype Serial
debugport 1
baudrate 19200
debugstart Active
RAM Defects
identifier {badmemory}
Global Settings
identifier {globalsettings}
inherit {dbgsettings}
{emssettings}
{badmemory}
extendedinput Yes
Boot Loader Settings
identifier {bootloadersettings}
inherit {globalsettings}
Resume Loader Settings
identifier {resumeloadersettings}
inherit {globalsettings}
Device options
identifier {ad6c7bc8-fa0f-11da-8ddf-0013200354d8}
description Ramdisk Device Options
ramdisksdidevice partition=D:
ramdisksdipath \boot\boot.sdi
Setup Ramdisk Options
identifier {ramdiskoptions}
description RAM Disk Settings
ramdisksdidevice partition=D:
ramdisksdipath \boot\boot.sdi