Just like the famous Trojan horse deception, malicious software often enters systems disguised as legitimate applications. To counter this risk, Windows offers a security feature called whitelisting, which restricts access to only approved programs.
Whitelisting allows administrators to create a list of trusted applications. Any new program attempting to run is automatically blocked unless explicitly authorized.
This feature is especially useful in environments where multiple users access the same device, such as workplaces, schools, or shared family computers. By implementing a whitelist, users cannot accidentally install or run malware-infected software, significantly reducing security risks. Additionally, whitelisting provides an extra layer of protection against emerging threats that may not yet be recognized by antivirus databases.
To configure a whitelist in Windows, users can utilize the Local Security Policy tool, available in Windows 10 and 11 Pro and Enterprise editions. While this tool is not included by default in Windows Home versions, it can be manually integrated. Local Security Policy enables users to manage Applocker, a built-in Windows feature designed to enforce application control.
Applocker functions by setting up rules, similar to how a firewall manages network access.
Applocker supports both whitelisting and blacklisting. A blacklist allows all applications to run except those explicitly blocked. However, since thousands of new malware variants emerge daily, it is far more effective to configure a whitelist—permitting only pre-approved applications and blocking everything else. This approach ensures that unknown or unauthorized programs do not compromise system security.
Microsoft previously provided Software Restriction Policies (SRP) to enforce similar controls, but this feature was disabled starting with Windows 11 22H2.
For users seeking a simpler security solution, Windows also provides an option to limit installations to only Microsoft Store apps. This setting, found under Apps > Advanced settings for apps, ensures that users can only download and install verified applications.
However, advanced users can bypass this restriction using winget, a command-line tool pre-installed in newer Windows versions that allows software installation outside the Microsoft Store.
Implementing whitelisting is a proactive security measure that helps safeguard PCs against unauthorized software installations.
While Windows Defender effectively protects against known threats, adding a whitelist further reduces the risk of malware infections, accidental downloads, and security breaches caused by human error. By taking control of which programs can run on a system, users can enhance security and prevent potential cyber threats from gaining access.
