HelpWindows7.com

[clement]

I have windows 7 on my PC and want to install Microsoft recently released Free Anti-Virus and Anti-Spyware package called Microsoft Security Essentials. But I am getting the following error:
"Can't complete the Microsoft Security Essentials Installation Wizard - Error code: 0x80070643"
Claudia: Click on start->Run->Type "Windows update" and hit enter. Click on check for Updates. Now, install ALL essential and optional updates. Reboot and try again.

[lambert]

Steps to solve microsoft Security Essentials installation issue in windows7
Step1:Run the clean up tool
Step 2: Please ensure that your Windows Installer service is running. Here are the steps to make sure whether or not windows installer service is running.
1.Click Start ->Run->Type services.msc , and then press ENTER .
2.Rt click on Windows Installer-> click Start . If Start is unavailable and the Stop and Restart options are available, it means the service is already started.
3. Try to install Microsoft Security Essentials again.

[duncan]

I had the same issue and solved it by starting Windows in Selective Startup mode
1.Start->Run->Type msconfig->Press Enter.
2.In the General tab, click Selective Startup, and then uncheck the Load Startup Items box.
3.On the Services tab, Check the option “Hide All Microsoft Services” and then uncheck all boxes for the services that remain in the list->OK
4. Restart to restart the computer.
5.Install Microsoft Security Essentials again.