How do I secure office computers, phones and Wi-Fi?

The short version

• Every device: automatic updates, a screen lock, encryption, and a standard user account for daily work.
• Router: new admin password, WPA3 or WPA2, current firmware, remote management off.
• Guests: a separate guest network, never the one your computers use.
• Old devices: anything that no longer gets security updates gets replaced or upgraded.
• Lost phone or laptop: a plan to lock or wipe it remotely.

Which devices count?

Every computer, phone and tablet that opens business email, files or banking. That includes staff’s personal phones if they read work email on them. Add each to the device list in your one-page security plan.

How do I secure a computer?

1. Turn on automatic updates for the operating system, browser and apps. CISA’s Secure Your Business lists updating software among its four essentials.
2. Set a screen lock that kicks in after a few minutes.
3. Encrypt the drive, so a stolen laptop doesn’t mean stolen data:
   • Windows: BitLocker on Pro, Enterprise and Education editions, per Microsoft. Many Home computers have Device encryption instead.
   • Mac: FileVault, per Apple.
   • Store the recovery key somewhere safe, away from the computer.
4. Use a standard account for daily work and a separate administrator account only for installing software. Malware gets less power that way.
5. Keep the built-in protection on: Microsoft Defender on Windows, and the Mac’s built-in protections.

What about Windows 10?

Microsoft ended Windows 10 support on October 14, 2025. Its Extended Security Updates page says businesses can buy up to three more years of security fixes, at $61 per device for the first year, with the price doubling each year after. Year one started in November 2025, and buying late means paying for the months already passed.

For most small businesses, upgrading to Windows 11 or replacing the computer is the better plan. Check whether each computer can run Windows 11 first.

How do I secure phones?

• Use a passcode or biometric lock, and automatic updates.
• Install apps only from the official app stores.
• Turn on Find My on iPhone or Find My Device on Android, so a lost phone can be located, locked or wiped.
• For staff phones with business email, consider a device management tool, so you can remove business data when someone leaves. Microsoft 365 and Google Workspace both include basic options.

How do I secure the office Wi-Fi?

The FTC’s Wi-Fi guide gives the router checklist. It’s written for homes, but the steps are the same for a small office:

1. Change the router’s admin username and password from the factory defaults.
2. Use WPA3 Personal, or WPA2 Personal if some devices can’t do WPA3. The FTC calls WPA3 “the newer — and best” option.
3. Update the router’s firmware, and turn on automatic updates if it offers them.
4. Turn off remote management unless your IT support needs it.
5. Replace a router that can’t do WPA2 or WPA3, or no longer gets updates.

Then set up a guest network for visitors and smart devices like TVs and cameras, as the FTC’s small business page recommends. Your computers stay on the main network, out of reach.

What about working away from the office?

• Public Wi-Fi is fine for browsing secure sites, but use your phone’s hotspot or a business VPN for sensitive work.
• Lock the screen whenever you step away.
• Don’t plug in USB drives you found or were handed at events.

What are the common mistakes?

• The router still on its factory password, often printed on a sticker.
• Visitors on the main Wi-Fi.
• Updates postponed for months because a restart was inconvenient.
• One administrator account everyone uses for daily work.
• No plan for a lost laptop. Encryption plus remote lock makes it an inconvenience, not a breach.

What if a device is lost or stolen?

1. Lock or wipe it remotely.
2. Change the passwords for accounts it was signed into, starting with email, and sign it out of every session. See the first hour after an account takeover.
3. If it held customer data and wasn’t encrypted, read what to do after a data breach.

How much does it cost, and how long does it take?

Most of this is free settings. A small office can work through the checklist in an afternoon. Router replacements and Windows 10 upgrades are the main costs; check current prices.

How does E-3 handle this?

E-3 looks after websites, hosting and business email, not office computers or routers. Put devices in your security plan under whoever handles your IT. For your website’s side, see our website care service.

Related questions

• How do I protect my business from ransomware?
• What are passkeys, and should we use them?
• How do I train staff on security?
• Why does my site say “Not Secure”?
• Back to cybersecurity basics

Sources

1. How to secure your home Wi-Fi network (FTC Consumer Advice)
2. Cybersecurity for Small Business (Federal Trade Commission)
3. Secure Your Business (CISA)
4. BitLocker drive encryption (Microsoft Support)
5. Device encryption in Windows (Microsoft Support)
6. Protect data on your Mac with FileVault (Apple Support)
7. Extended Security Updates for Windows 10 (Microsoft Learn)