Norton Internet Security automatically downloads definition updates regularly and secures your computer from all types of viruses and unknown threats. In addition, Norton Internet Security monitors your Internet activities to protect your computer from the Internet-based threats that exploit software vulnerabilities.
If you suspect that your computer is infected, you can run different types of scans manually and prevent virus infections on your computer. For example, you can manually scan a folder to which you download the Internet files.

You can manually run the following types of scans:

You can use the Insight Protection option to perform an Insight Network scan for additional protection. When Norton Internet Security performs the Insight Network scan, it uses the virus definitions that are available locally and hosted in the Cloud. Norton Internet Security provides additional protection by using the most recent definitions in the Cloud, apart from the definitions that are available locally on your computer. Norton Internet Security performs an Insight Network scan only when the Insight Protection option is turned on. By default, the Insight Protection option is turned on. You can see this Insight Protection option under Computer Settings in the Settings window.

You can also use Idle Time Scans to protect your computer against infection without compromising the performance of your computer. Idle Time Scans automatically detect the idle state of your computer to run a Quick Scan or a Full System Scan.