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Windows Server Hardening Best Practices

By Nathan Zych, Chief Executive Officer · · Updated July 10, 2025 · 4 min read

Windows Server Hardening Best Practices

Windows Server Hardening Best Practices

For decades Windows has been the most used operating system for business organizations. However, it’s popularity has made it the primary target of cyberattacks. In fact, 83% of all malware attacks are targeted at Windows computers.

While Windows does have significant security vulnerabilities which are constantly being exploited by hackers, the remote/hybrid work model has created new opportunities for malicious entities to access business data. Therefore, it is more important than ever for businesses to implement measures to keep their systems safe from breaches. This is where windows server hardening plays a significant role.

Server hardening is the practice of limiting the attack surface that malicious actors can exploit, removing vulnerabilities, and closing loopholes in a server. Many security compliance standards such as PCI-DSS, and industry certifications like ISO 27001, require server hardening.

The first step in this process is establishing security baselines. Server security baselines are pre-configured Windows settings that enforce security. The configuration suggested by Microsoft protects domain controllers, servers, computers, and users. It contains a series of instructions, automated scripts, and other procedures necessary to reach the baseline security level. The Windows Server Security Baseline zip file is available from the Microsoft Download Center.

After establishing a network security baseline, the server hardening process can truly begin. In this article we cover 5 of the most critical Windows hardening best practices which businesses can use to ensure their servers are fully protected from cyberattacks.

Keep Windows Updated

Microsoft works hard to stay on top of security vulnerabilities within its products. Constantly updating is the easiest and most effective way to avoid being hacked.

The latest Windows 11 update focused primarily on securing new features that accommodate flexible work environments work, such as:

  • Chip-to-cloud protection
  • Smart app control
  • Enhanced phishing detection
  • Default credential guard
  • Default local security authority

Businesses should also make an organized effort to keep browsers, plug-ins, 3rd party apps, and antivirus software up to date. Hackers commonly use 3rd party software as avenues to access networks.

Disable Unused Services and Applications

Minimizing the attack surface will dramatically lower vulnerabilities within a closed network. In many cases, an unused service or outdated application is how a cybercriminal gains access to a network. In fact, this can even apply to unused devices, as was the case when a water treatment facility in Florida was breached through an unused computer.

Microsoft provides guidance on disabling Windows Server per user and system services to help organizations looking to reduce their attack surface here.

Limit Internal Permissions and Access

Physical and digital access control is needed to harden the Windows server environment. Establishing internal protocols to manage who is using the server is the most effective way to limit access. Additionally, regular log reviews and audits on the server can identify suspicious use and identify vulnerabilities in the instance of a breach.

Regular IT security training helps organizations build a culture of proactivity. Users are common targets for ransomware, phishing, and malware attacks. Security training and consistent awareness are vital in limiting threats.

Set Strong Password/Login Policies

Strong password policies should always be implemented and enforced. Windows has built in measures to protect users, however it is still essential that strong password creation and management practices are followed.

All users, especially those with administration access, should:

  • Never reuse passwords
  • Rotate credentials and keys
  • Never use common passwords – dates, words, etc.
  • Use 2-factor authentication

Limit External Access

After the blockbuster Solar Winds hack, the Cybersecurity and Infrastructure Security Agency confirmed in a letter that “better cyber hygiene – specifically, blocking SolarWinds Orion servers from outbound internet traffic – could have helped prevent the supply chain attack.”

There are various ways to limit and secure external access to a server. For example, IP filtering allows only IPs that need access, denying all other traffic. Another method is through a firewall. Windows already has a firewall in place, however configuring it to fit a network’s specific environment will improve security.

Remote work empowers employees to work from anywhere. However, access from unsecured WIFI networks creates an opportunity for hackers. One way to limit these threats is to require a VPN or reverse proxy on all external network connections.

Leverage the Tools Built into Windows

Establishing Windows server baseline security and keeping the OS updated will prevent a substantial number of cyber threats. Microsoft has shown an even stronger dedication to improving security since developing more advanced cloud-based collaboration products.

Additionally, to fully secure a network, it is required that both company leadership and staff buy into proactive cyber security practices. On the other hand, if a network is outdated and misconfigured, hackers basically have the green light to breach the network.

For business organizations who need help with establishing aggressive security protocols to harden their servers to the max, look no further than Outsource IT. We are Canada’s premier provider of business IT security, securing organizations now for over 20 years. Coupled with our fixed cost managed IT services, we provide a complete solution to all your business IT needs regardless of business size or industry. Contact an Outsource IT account manager or click here to learn more.

GET UNLIMITED REMOTE AND ONSITE BUSINESS IT SUPPORT FOR A FIXED FEE

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About the author

Nathan Zych, Chief Executive Officer

Written and reviewed by the Outsource IT team, a Burlington, Ontario managed IT services provider supporting businesses across the GTA for over 20 years. Meet the team.

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