Windows Defender definition updates for Windows 8 Publisher's description
By default, Windows Defender is designed to install and run updates automatically.
By default, Windows Defender is designed to install and run updates automatically. If you have disabled this feature or if you encounter problems updating automatically, you can manually download and install the latest Windows Defender definition updates for your computer.
System Requirements:No special requirements.
Program Release Status: Major Update
Program Install Support: Install and Uninstall