Using Microsoft's Windows Defender, a full system scan takes hours to complete. For instance, my system has an SSD and three HDDs. The custom scan, then, allows you the same in-depth scanning functionality as a full scan, but you choose the locations to scan. But for most people, a single full scan per month is usually enough. Some security experts advise completing a full scan every two weeks. When to use? Use a full scan when you need to check your entire system. In that, a full system scan is a thorough, in-depth analysis of everything on your system. All hard drives, removable storage, and network drivesĪ full system scan takes several hours, depending on how much data you have stored.Depending on the antivirus program, the antivirus will scan the following objects: Full ScanĪ full scan performs a thorough check of your entire system, inside and out. The scan names are seemingly self-explanatory. This option is sometimes referred to as a 'Smart' scan. In general, these options are usually a 'Full' system scan, a 'Custom' system scan, and a 'Rapid/Hyper/Quick' scan option. Most antivirus programs have two or three different scanning options. If the file attempts certain activities on your system, the antivirus will quarantine the file.Īntivirus suites combine these two defense tactics and many others to keep your system free of malicious programs. Instead, the antivirus monitors the actions of the file, inspecting the interactions on your system. In this case, the antivirus doesn't have a signature in its database to compare a file against. If you download a file with a known signature, your antivirus should take care of it-but mishaps do happen occasionally.Īnother antivirus trick is using behavioral analysis to assess unknown viruses. Similarly, your antivirus suite has a long list of known malicious file signatures. The antivirus checks the properties of the file to make sure it isn't part of a malicious program.

When a file is modified, your antivirus scans it to ensure those changes aren't harmful to your system. Your antivirus primarily works in the background of your system. Before considering exactly what each antivirus scan type does, let's brush up on antivirus general role.

Antimalware scan