But such machines are not safe from malicious software threats which can affect them any time such PCs come in content with external storage mediums such as CDs, DVDs, and flash storage drives.

While the built-in Windows Defender relies heavily on the Microsoft Windows Update service to deliver the latest add-ons, upgrades, and definition archives, many Windows users do not have PCs that are connected to the internet.

Microsoft Windows Defender Definition Updates 64bit is a crucial security addon that enables the core antivirus service running on all modern versions of Windows OS to get access to the latest antivirus definition and gain the ability to detect, quarantine, and erase a wide array of software threats on desktop and laptop PCs.