The problem only occurs at times. To reproduce the problem, I just
use the computer normally, and at each logon check the event viewer
and running processes to see if a profile unload failed. I don't
have any special terminal software or other logon software installed.
I find that if I wait for a little bit after logging off before
logging on again, no running programs from the previous logon are
present, but if I log on just after logging off, they will be if the
profile unload fails. That still shouldn't be the case. My brother
frequently goes on his account right after I go off; there shouldn't
be a time limit to wait in order to prevent this.
I noticed an interesting thing about XP and fast user switching which
would likely stop this problem. When logging on, the first logged on
user is given session ID 0, as shown in task manager, but if I
'switch' to another user, the user is given a different session ID.
It seems that no two users are given the same session ID when using
fast user switching. But when logging off all users and then back on,
it is back to session 0. And if I just log on as a user, log off,
and then on as another user without using the 'switch user', they
both are session ID 0.
The same thing happens when using classic logon and on 2003. All
logons are given session ID 0. I did some reading in the platform
SDK and some sites about stuff, and it seems that these sessions
literally create an isolation. Messages sent from a process in one
session ID are not visible to processes in another, windows created
only appear on the desktop associated with that session of the
process that created the window, etc.
Ideally, running classic logon always as session 0 'should' work
because ideally when logging of, the processes ran 'should' close, so
the next user to log on would have nothing to access. But this does
not appear to be the case at all times.
A few moments ago I logged in as administrator to do some minor
changes, and I ran EPIM to take some notes of things. When I logged
of and back on as a regular using, 'explorer.exe',
'essentialpim.exe', 'seamonkey.exe' were still running as
Administrator, event viewer showed the usual UserEnv messages, and
EPIM appeared on the system tray. My guess is something like this
happens:
Logon Administrator : Session ID 0
Run EssentialPIM : Session ID 0
Do some stuff
Logoff Administrator : Profile unload fails, a few programs continue
running
Logon Normal User : Session ID 0
Explorer runs, and at startup broadcasts 'TaskbarCreated' message
All processes in session 0 get this message, EPIM adds system tray
icon like it is supposed to
If each logon, even in classic mode, is given a separate session ID
as is done in fast user switching, this would not happen, even if the
profile unload fails and the programs continue to run waiting for the
profile to unload:
Logon Administrator : Session ID 0
Run EssentialPIM : Session ID 0
Do some stuff
Logoff Administrator : Profile unload fails, a few programs continue
running
Logon Normal User : Session ID 1
Explorer runs, and at startup broadcasts 'TaskbarCreated' message
All processes in session 1 get this message
Programs that may continue to run in session 0 are isolated
If I log on as administrator again, it would be ok to reuse session
0, but for a given boot, no two users should be assigned the same
logon session ID. I.E. if I log on as Normal User again, it would
be session 1, etc.
This would not prevent a profile from failing to unload, and would
not prevent the processes from continuing to run, but it will prevent
a user from a later logon from accessing the processes in the current
logon.