Some user might have came into contact with following error and we have discussed here and suggest here some of troubleshooting tips.
My PC some time says while I shutdown “Other people are logged onto this computer. Shutting down Windows might cause them to lose data. Do you still want to continue shutting down?”
There are many reasons which can cause this specific problem and it is difficult also to diagnose it. There is lot of information a doctor solving this problem will ask you like
What specific McAfee product you are using?
Are you also running a firewall or not?
Are you connected to a network or the internet?
But today we will discuss a general solution to this problem and stick to the basics. The message prompts telling that somebody has logged in to your computer with a user account other than the one you are using to log in with. That person might be using any user account to log in sitting elsewhere on your network or over the net.
The first thing I would say to do is go to the Control Panel and click on the User Accounts icon. It will show you what user accounts are listed for your computer. Change passwords for all user accounts. You can do it by logging in a system administrator. It is better if you delete all accounts other than the one you are using.
I am sure these simple steps have solved your problem now. Even after doing all this you should also make it sure that you are running firewall because cracking passwords is not a big hurdle to crackers. Firewalls are designed to keep others from committing such evil acts like accessing your computer remotely.