Logoff script to change user

Question

Using Windows 2003, I'm look for a way to create a "logoff script" that will continue with the current logoff then immediately login another user. So, "UserA" logs off. Script fires to login "UserB".

This is part of an application upgrade for a computer where we have written the 'shell'; similar to a kiosk application. For the upgrade we need to logon as 'Adminstrator' then, when the upgrade has completed, logoff 'Administrator' and logon as 'sample_user'. We would like to accomplish this WITHOUT rebooting.

Note, I do not want a script that will initiate the logoff (i.e. "shutdown"). I'm looking for a script that will run upon the user logging off (set via Group Policies). As above, the script should log a different user on.

Thanks.

Answer 1

Don't think it's possible in the stated way (script at logoff).

You'd have to set the machine to logon automatically as a specified account and then log off (having it log on automatically for you) and then you'd have to disable that feature again afterwards, by placing a temporary logon script... generally sounds messy.

The actual setting can be made using tools like Microsofts Shared Computer Toolkit or similar (not so sure how the "normal" registry auto-login behaves at manual logout but I've had an XP kiosk that would automatically log on instantly, even if you logged out manually - you had to override it using some key like shift+logoff to be able to manually specify the login again, so somehow it can be made).

The "easiest" way might be to replace msgina.dll with someone of your own making...

But why are you doing this? Just use runas and start whatever you need to do as that other user without logging off the console user - it's a multi-user system afterall? The desktop is just fluff ^^

(This will anyhow require that the user credentials are available to your script, which kind of makes it redundant as you compromise the security of that account - defying the purpose of having that second account in the first place, for whatever purpose it exists?)

Answer 2

I would try setting the registry to autologon with the user you want, and then simply logging off the admin user. That should log your kiosk-user right back on.

Answer 3

Not sure how to login another user once the current user logs off (not sure if windows would let you...)

But you can use shutdown to logoff:

shutdown /?

Answer 4

Here's some ideas that probaly fall into the "cheap hack" category:

How about logging in at UserB in the first place, and then using runas /user:userA <cmd> to run the first part of the install process?

If that's unacceptable, I know there's a way to make Windows workstations (those that aren't part of a Domain) automatically log in into a certain user account after a restart. Perhaps if you looked into which Registry changes happen, and duplicated them, a reboot would automatically log in that user. (Of course, as a final stage, after userB logs in, you would have to revert those changes :-)

It also occurs to me to wonder if perhaps there's a way for a service to force an open "login screen" to log in as a certain user. Maybe using some method like the way the Remote Desktop does it remotely... If that's possible, then you could create a service that you install before logoff of userA, that would trigger the login of userB.

Answer 5

You can script it with VNC (there are many free versions, take your pick). Set up a VNC server process on the machine to listen on localhost. When the user logs off, your logoff script will connect to the machine using VNC and send the keystrokes necessary to log on the next user. VNC uses the RFB (remote framebuffer) protocol; there are libraries for most popular languages, so you should be able to get something working quickly. Or there are related tools that might help.

Answer 6

If you were to run something like this as a normal script in a given language, it would most likely not work as when you log out of your account, all processes should be killed along with your running script.

You might be able to create some sort of 'service' that would run on a service account (i.e. always active) that would automatically do this user switching for you.

My bets are on Windows Powershell, although I'm not entirely sure what functionality it has as far as actually creating a service.

A quick search brings up the following (The second link is to a forum but it mentions running Powershell as a service and sending that service a parameter which would be the path to your user switching script)

How to Create a Windows Service using Powershel

Powershell Script as a Windows Service

Answer 7

I don't have a Windows 2003 server or a system with a "Group Policies" setup to test my hunch but you could take a look at SU ("switch user") for Windows. Originally part of the Resource Toolkit this has been extended to a new SUperior SU. Do post the results/script if this works.

Answer 8

You could approach this from the perspective of building a remote control utility (like VNC, etc). The big thing here is that if you want access to the Logon screen (i.e. the CTRL + ALT + DEL / username/password) part, the only kicker is that a Windows Service is the only component that can access this, so you'd have to create one.

The only problem I see with this technique as a whole is that even if you spent a great deal of effort getting it to work (and it would be a pretty big effort), the chances of this working successfully with the whole thing originating from a logoff script (i.e. when stuff is shutting down) are low even due to the number of things that can go wrong when logging back on as Administrator.

Just remember that for anything you need to run as an Administrator, there are easier ways in Windows to make that happen (such as Run As, changing the user permissions on the items that need to update, etc).