You can't bootlog the Last Known Good Configuration.
You can't set the computer to always boot to the Last Known Good
Configuration, you can only select this option with the use of the F8
boot options. If you understand the registry and if you are ready to
try advanced techiques you could try changing the Control Set numbers at
HKEY_LOCAL_MACHINE\SYSTEM\Select and swith the Default and Last Known
Good values. Be warned that this can be risky business and it won't
solve your problem!
If the computer boots properly to the Last Known Good yet refuses to
then subsequently reboot to the default Control Set then there is
something adding startup items to the registry *after* the computer is
booted. You would have to compare the startup items in the Default and
LKG Control Sets.
At this stage you should make sure that the machine is free of malware
and you should do a clean boot to try and figure out what might be
causing the default boot to fail:
How to configure Windows XP to start in a "clean boot" state
http://support.microsoft.com/kb/310353
How the Boot Process and the Last Known Good Configuartion Work.
When you boot the computer and select a boot option ntldr reads the
HKEY_LOCAL_MACHINE\SYSTEM\Select key to determine which Control Set it
should load. The Select key contains the following values:
Current
Default
Failed
LastKnownGood
These values typically contains data as shown here:
"Current"=dword:00000001
"Default"=dword:00000001
"Failed"=dword:00000000
"LastKnownGood"=dword:00000002
The data may be different in your computer, if you have had failed boots
you may have different numbers (like 00000003) and the numbers assigned
to the values may be different than shown above. These numbers tell
ntldr which Control Set to load, the Control Sets are also held in the
HKEY_LOCAL_MACHINE\SYSTEM key, typically:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002
When you boot the computer normally ntldr looks for the "Default" value
and loads the Control Set assigned to it, in the above example it would
load HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001, if you boot to Last Known
Good ntldr looks at, of course, the "LastKnownGood" value and loads the
corresponding Control Set, in this example it would load ControlSet002.
The Last Known Good set is only copied and recorded after a user
successfully logs on. In the above example, if you boot normally,
Windows will be booted using ControlSet001, after a user successfully
logs on the ControlSet001 will be copied to ControlSet002 and the
control set number will be recorded in the Select key. The value of the
Select key and the ControlSetnnn of the "LastKnownGood" configuration
will not change until the next successful logon. Booting successfully
to Safe Mode does not change the "LastKnownGood" Control Set, in only
changes when booting Windows normally.
So now it becomes apparent that something is added to the Default
Control Set *after* Windows is booted and on the subsequent reboot
whatever was added to the Control Set is preventing Windows from booting
properly. A service, application or some kind of malware is adding
something after the booted Control Set is copied over to the Lasst Known
Good set.
John