MSE icon disappeared from system tray

I am running Microsoft Security Essentials (MSE) 2.0 on Windows XP SP3. It gives me an amazing feeling and I am really happy with its performance. However the only problem that I have noticed with MSE is that most of the time, twice in a week, my system tray icon gets vanished. I have checked the settings just to make sure it is not set to hide when it is running. But I am not hiding the icon and MSE is still working. Then why there is no tray icon. How can I add the MSE icon to the system tray? Any ideas? Is there anyone else who got this problem?

I don't know why is this problem occurring or never heard about it. It might be because I have never used it but still since its an anti-virus I still never seen happening this to other. Moreover there is no specific, or I must say hard and fast rule, why system tray icons tend to disappear. So the only solution that I think can solve your problem is restart your computer. If this doesn't solve your problem then I need you to elaborate what the problem is.

There are two solution to this system tray icon disappeared for MSE. It can basically occur if the MSE itself failed to launch and thus you are unable to see its icon; or it is set to hidden. So fix this, if the icon is hidden, then you can right click on the taskbar and click on Properties option. You should see an option with title "Hide Inactive Icons". Uncheck it and then click on OK button. You should see all the icons that are hidden or inactive. Make sure you can see the Microsoft Security Essentials icon appearing in the list. If it is not in the list than you can try to launch the application manually. Go to Start - Programs - Microsoft Security Essentials. Start the application manually. Re-check if you can see the icon in the taskbar now. If none of these operations work then there might be the chances that your Windows is not configured to start MSE automatically after you boot computer. You can perform necessary changes by going to Start, Run, type MSCONFIG and press Enter button. Go to the Startup tab and make sure the Microsoft Security Essentials is listed in the list in front of you and also it has a check mark.

In general, an application tends to disappear from the system tray icons if it is closed or crashes. So you have to check which is applicable in your case. Also make sure it is present but disappeared since you have a lot of applications listed in the system tray icon list. To check this, click on the upward pointing arrow which is present before the system tray icons. If it is there then you can click on Customise and then Show icon and notifications. If it isn't then the problem is beautifully explained by someone else above. Refer that post and you should get it solved soon.

This generally occurs if your computer has closed unsafely during its last shut down. Some time it even occurs if you keep your computer in hibernation for a longer period and later on it shut downs automatically due to some reason, lets say power failure or so. In either of the cases you may notice that the Microsoft Security Essentials icon disappears although it was running. So to remedy, simply go to the Task Manager (right click on taskbar and select Taskbar). Go to Processes tab and select MSE from the list that appears. Click on End Task button appearing at the bottom of the window. Now restart your MSE application from Programs in Start. The icon should reappear. Just give it a try. Who knows what can help you!

First make sure you have removed all other antimalware applications such as Norton, McAfee, AVG, etc. from your computer. You can also use the removal tools for the same if you are not sure. Did you recently updated Adobe Flash? It might have installed McAfee Security Scanner on your computer with out your concerned. Make sure it isn't the case but if it is then remove it from your computer immediately. Uninstall or disable Windows Defender from your computer. Make sure that you have latest patches and service packs installed on your computer. Also verify that your computer clock is configured properly. Do you have Windows Firewall running? If not then do it and set it to its defaults. Go to Internet Explorer and reset all security zones to default level. MSE uses it to some extent. Once everything is done, reboot your computer.

This is a very old, and often described Windows-XP misbehavior. Check in your Windows Services if you have the required services on. For this go to Start, then Control Panel, then double click on Administrative Tools and then double click on Services. Now check if the services such as Automatic Updates service, Background Intelligent Transfer Service (BITS), Windows Installer, Cryptographic Service etc are set to automatic and currently set to START.