Is Microsoft Defender Enough for Business? Defender vs Antivirus

Quick answer: free Defender vs Defender for Business vs third-party

The three options are not really competitors at the engine level. The difference is what you can see and do across all your devices.

Prices are approximate, as of October 2026, from Microsoft's Defender for Business page for Singapore, in US dollars excluding GST on an annual plan.

What the free Microsoft Defender Antivirus does

According to Microsoft Learn, Defender Antivirus is built into Windows 10, Windows 11 and Windows Server. It uses machine learning and cloud-delivered protection, and can block threats based on behaviour, including fileless malware. It is the same engine used in Microsoft's paid business products.

What it does not give you is a business view. Each PC is managed on its own, through the Windows Security app. If a staff member switches protection off, misses updates for months or gets an alert, nobody else finds out. There is no record you can show an auditor or insurer, and no way to isolate an infected laptop remotely.

What Defender for Business adds (EDR and central management)

Microsoft's Defender for Business overview describes it as an endpoint security product for businesses with up to 300 users, based on Defender for Endpoint. Compared with the built-in antivirus it adds:

• Endpoint detection and response (EDR): records activity on each device so attacks that get past antivirus can be spotted and traced.
• Automated investigation and remediation: looks into alerts and can fix common problems without someone doing it by hand.
• Automatic attack disruption: can contain an attack in progress, for example by isolating a device.
• Vulnerability management: lists missing updates and risky software across devices.
• One console and monthly security reports covering Windows, Mac, iOS and Android.

According to Microsoft's Defender for Business FAQ, each user licence covers up to five client devices. Windows or Linux servers need a separate Defender for Business servers licence, listed at US$3 per server.

Price per user and when you already have it

If you already pay for Business Premium, you own Defender for Business. Check the Microsoft Defender portal: if your devices are not listed there, they are not onboarded, and you are paying for protection you are not using. Our guide on whether Business Premium is worth it compares the full bundle with Standard plus add-ons.

Management, not the product, is usually the gap

Choosing between good antivirus brands matters less than the basics around them. Typical weak spots are a laptop that was never onboarded, alerts going to a mailbox nobody reads, or updates months behind. Our ransomware first-response guide covers what happens next if that occurs.

Note on round-the-clock monitoring: in Singapore, managed security operations centre monitoring is a licensable service under the Cybersecurity Act. A small business normally gets alerts to its own email and a provider who helps when you forward one, rather than a 24/7 security centre. Our BYOD and MDM guide covers the device-management side.

Do it yourself or get help?

If you are on Business Premium, start in the Microsoft Defender portal's setup wizard: onboard devices, apply the default policies and set who receives alerts. If you are on Basic or Standard, add Defender for Business licences first. Test on one PC before rolling out.

If you want it done for you, our Antivirus & Endpoint Protection Rollout (S$390) sets up Defender for Business, Bitdefender or ESET in your own account and installs it on up to 10 devices, with alerts going to your email. To keep it maintained, Protect Standard (S$19 per user per month, minimum 3 users) checks protection, encryption and updates every month and helps when you forward an alert. Licence fees are paid by you to the vendor.