Here is another example of how QuickBooks employees ("QuickBooks Team" members really mean well, but because most have no experience in working out in the "real world" where this software is used by business organizations, the answers don't really solve the problem.

In a perfect world, the solution of using Messenger would work, just the same as picking up the phone or walking down to someone's office to tell them to log out. Unfortunately, in the real world, things are not so simple.  The person who is logged in may be out for lunch, may be sick and left for the day, maybe logged in the day before and is now on vacation for two weeks, maybe was fired and never will be back .... who knows????  Or maybe the need for single user mode happens at night when the poor person working on the system discovers the need to go to single user mode and they are the ONLY person in the office!  Messenger is totally worthless in these instances, and they happen more often than you would think. But unless the people answering these questions actually were forced to work out in the real world where these things happen, they don't have a clue and can't provide meaningful answers.!!!

And the people who DESIGN QuickBooks don't have the relevant experience either, or they would design systems that are far more beneficial. The idea that the Admin can set a time limit on how long users can remain logged on actually contribute to these problems!  The shortest period of time we can restrict a user to is 1 day, and it goes up to 90 days or so. How stupid! The shortest period should be in terms of HOURS, not days. And it should be measured by inactivity on the system!  

Let's do an example:  Say you choose to set the inactivity time limit to 2 hours: this means that as long as the user is active on their QB system frequently, they have no problems. If they are inactive for two hours straight, the system logs them out! People will complain about this, but it keeps active users in and does not tie up the system when people are not using the system for 2 hours or more.

QuickBooks is a nice system, with some glaring problems. It could be a great system if the people designing it and providing answers to users actually had experience that was gained in work relevant to the people to actually use the system!