In this tutorial you can find detailed instructions on, how to fix Windows Installer upgrade error issues in simple clicks.
1.Click Startup and type cmd in the searchbox, then double click on cmd.exe.
2.Type gpupdate and press enter, then you can destroy virus on your computer.
When the software has no reply to your operation or runs very slow, you can choose to terminate it and restart.
1.Right click on the taskbar, choose Start task manager.
2.A new window will open, and find the application you want to stop.
3.Click on it, click End Task.