Why should you use MSE?
Microsoft Security Essentials (MSE) is compatible with computers running Windows XP and later. It even comes pre-installed in Windows 8 and 8.1. Couple MSE with any good anti-malware protection suite, and you'll have a complete PC protection package.
An anti-virus software not only keeps a computer safe from viruses and malicious programs, but also keeps it fast and snappy. If you do not want your computer to slow down after installing antivirus software, and don't require ultra-tight security, then Microsoft Security Essentials will more than fulfill your requirements. What's more? It's free and compatible with all the latest builds of Microsoft Windows operating systems.

It is always recommended that you keep your antivirus software running at all times, but the same is not applicable when you are either installing or troubleshooting a software (malfunctioning), or a hardware driver. Most of the antivirus software are very easy to disable, but MSE is somewhat complicated in this regard. You can't just right-click on its icon in the system tray and disable it. This article will show you two ways to disable Microsoft Security Essentials―temporarily and permanently.

Disable MSE Temporarily

1. Go to 'Start Menu' by clicking on the 'Start' button.
2. Open Microsoft Security Essentials after you find it by entering the search term as 'Microsoft Security Essentials'.
search for mse

3. Go to 'Settings' tab and select 'Real-time protection' from the left column.
4. Un-check the box labeled as Turn on real-time protection (recommended).
turn off mse

5. Click on 'Save changes' and then close Microsoft Security Essentials.
disable microsoft security essentials

You have successfully disabled Microsoft Security Essentials. Its real-time protection won't turn on even after you restart your PC. However, MSE will still start with Windows.

Disable MSE Permanently

If the technical support team, or you, do not want it to run even during system startup, then you either need to remove it from the startup list or uninstall it completely from your computer.

Removing MSE from Startup List

1. Press Start+R keys simultaneously on your keyboard on open 'Run' menu.
2. Type 'msconfig' as shown in the screenshot below, and click on the 'OK' button.
enable private browsing mode in Google chrome

3. Go to the 'Startup' tab and, un-check the box left to the entry for 'Microsoft Security Client'. Click on the 'OK' button, and then select whether you want to 'restart' or 'exit without restart'.
remove MSE from startup list

4. The changes will take effect only after you restart your computer.

Uninstalling MSE

1. Open 'Start Menu' and click on 'Programs and Features' after searching for it.
open programs and features

2. Now, search for 'security essentials' in the search bar located at the top-right corner of the window.
3. Right-click on 'Microsoft Security Essentials' after it shows up in the search results, and then click on 'Uninstall'.
uninstall MSE

4. Follow the on-screen instructions to get rid of MSE permanently.

If you have disabled Microsoft Security Essentials temporarily, then do not forget to turn it back on again later.