Hi MsJeni,
Welcome to Microsoft Answers!!!
1) Does this message come up every time you try to shutdown?
You may perform a clean boot to see if any third party application is conflicting with the Task Scheduler
Method 1:
To perform a clean boot on a computer that is running Windows Vista, follow these steps.
1. Click Start, type msconfig in the Start Search box, and then press ENTER.
If you are prompted for an administrator password or for a confirmation, type the password, or click Continue.
2. On the General tab, click Selective Startup.
3. Under Selective Startup, click to clear the Load Startup Items check box.
4. Click the Services tab, click to select the Hide All Microsoft Services check box, and then click Disable All.
5. Click OK.
6. When you are prompted, click Restart.
7. After the computer starts, check whether the problem is resolved.
If your issue is resolved, follow the How to Determine What is Causing the Problem section in the KB article to narrow down the exact source.
http://support.microsoft.com/kb/929135.
Also, see the section on how to return your computer to a Normal startup mode
This article is intended for Windows Vista but it holds good for Windows 7 as well.
If the above method did not resolve the issue you may try the below method and check if the issue is resolved.
Method 2:
1) Click Start
2) Type Task Scheduler
3) In the new window find Active tasks
4) Look for Trigger options under Active Tasks
5) Disable any application scheduled “On Workstation Lock” and “Disconnect from User Session” under Trigger.
Note: Make sure you don’t disable any Microsoft Services.
Chances are you have something in the Task Scheduler (a scheduled task = backup software, scheduled Anti Virus scan or updater, Disk defrag, etc) which is causing this problem. If so, list what scheduled tasks are there.
First what you can do is to let the Task Scheduler to execute shutdown tasks, and stop tasks that are already running for one time without force shutting down the computer. Then reboot the computer and see if the issue persists in the next shutdown.
A task can be scheduled that is triggered often enough to cause 100 percent of the CPU to be used. If this problem occurs, the system can become unusable.
To correct this problem, disable the task and then change the trigger for the task. For more information about how to change a task, see Change an Existing Task.
If the system is unresponsive because the task is using all of the system resources, perform the following steps:
1. Restart the computer in safe mode (the Task Scheduler service does not run in safe mode),
2. In the /Windows/System32/Tasks folder, rename the file for the task, or delete the file.
3. Restart the system in normal mode and then redefine the task.
Also Update all hardware and antivirus software to the latest versions.
You may also create a New User Profile and check if it is an issue with corrupt user profile.
Access the link below to create a New User Profile.
http://windows.microsoft.com/en-us/Windows7/Create-a-user-account
Method 3:
I would also suggest you to run an online malware/virus scan on the computer.
http://onecare.live.com/site/en-US/default.htm
Hope this information is helpful
Regards
Varun J: MICROSOFT SUPPORT
Visit our Microsoft Answers Feedback Forum
http://social.answers.microsoft.com/Forums/en-US/answersfeedback/threads/ and let us know what you think