Losing your laptop is a costly inconvenience at best, and a significant threat to your digital security at worst.
While the practical consequences may vary depending on who gets their hands on your device — a petty thief who's just looking to pawn the hardware versus someone with the basic knowledge to hack your passwords (or worse) — there are a number of steps you can and should take to mitigate any possible damage. 
You can also implement preventive measures to minimize the security risk if your laptop is ever lost or stolen. 

Change your account passwords.
This is the first step most security experts recommend if you lose possession of your laptop. If someone else can log into your device, then they'll likely have access to most or all of your online accounts — especially if you use your device's or browser's keychain to autofill your usernames and passwords. 

Start with your email password. Make that password long, strong and unique. Your email account is the key to your other accounts, as a thief can use it to reset login information.
Then enable two-factor authentication (2FA) on your email account if you haven't already. You'll also want to prioritize global logins, like those on your Apple ID or Microsoft accounts, that grant access to other data and services. 
Once your email account is secure, start working your way through other accounts, including social media and bank logins.
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Clear autofill from your browsers.
If you have autofill enabled in your web browsers, all a thief need do to access your accounts is open that browser. Turn off automatic sign-in options and delete your saved passwords. 
To do this in Chrome, go to chrome://settings/passwords and toggle off Auto Sign-in. You can also clear your browsing data to remove saved logins from any devices that sync with your Google account and sign out of Chrome remotely. Firefox and Safari have similar options in their preferences and settings menus. 

You should also remove all saved payment information from your online e-commerce accounts, such as Amazon. 

Deauthorize your device.
You may also be able to remotely revoke your laptop's access to online services. Apple has an option to remove devices logged into your Apple ID. You can remove computers from Google's trusted device list, deregister devices from your Amazon account and log out remotely from Facebook.

A quick Google search will bring up instructions for other services — a good bet for those you use to log into other third-party sites. 
You can also turn off any auto-sync features between linked devices, such as your phone and tablet, to prevent your information from being updated on your missing laptop. 

Track your laptop's location and use remote-wipe features.
This tip generally only works if your lost device connects to the internet, which makes it more useful for mobile devices. But if your laptop does go online, you can use built-in "find my device" features to locate and control it. 
If "Find My" is enabled in advance through iCloud for your Apple computer, you can see connected devices on a map and take several actions to secure them, including marking them as lost (which locks them and disables Apple Pay) and activating remote erase.

Windows users have similar options to locate and lock devices from afar. There are also third-party programs like Prey that give you options for remote control.

Notify your financial institutions.
Just as you would if you lost your physical wallet, contact your bank and credit-card companies about any financial accounts that autofill when you make a purchase or that you have saved on e-commerce sites. You can freeze your debit and credit cards and let your financial institutions know about the possibility of suspicious activity. 
In the meantime, you should also keep track of your account activity by checking it online every couple of days after your laptop goes missing. If personal information such as tax returns, bank account numbers or Social Security numbers are on the stolen laptop, then consider freezing your credit records.

Notify your employer.
If you lose your work computer, let your employer know immediately. Your company may have specific protocols to follow, additional options to track or wipe the device, or software installed that can recover your data. Plus, your work laptop is your employer's property — not yours. 

File a police report — and report the loss to the manufacturer.
Truthfully, this step may not yield results, but it's possible that your device can be recovered if someone tries to sell it or get tech support. File a report with local law enforcement, who may request your laptop's serial number (more on that in a minute). Both ASUS and Dell will open stolen device cases. 
A police report may also be required if you want to submit an insurance claim.

Steps for prevention.
You can't predict whether your laptop will be lost or stolen, but you can take preventive steps to protect it if it ever is. 

• Write down your device's serial number so you have it on hand. 
• Secure your laptop with a password. 
• Enable limits that will lock up your device after a certain number of failed login attempts.
• Use a secure password manager instead of device and browser autofill to keep track of strong, unique logins. 
• Consider a physical security key, like YubiKey or Google Titan, for 2FA. 
• Set up automatic backups from your laptop in case you need to remotely wipe it. 
• Use full-disk encryption to secure your hard drive (but keep a backup of the encryption keys). 

The goal is to make it difficult for someone to get your valuable information from a lost or stolen laptop, Tarighat says. Putting up as many barriers as possible — requiring a thief to break into your operating system, overcome 2FA, unencrypt your hard drive and break lots of individual unique passwords — can help protect your data. 

Thanks ​Tom's Guide 

Taking a proactive approach to security can help reduce the risk of a ransomware incident. Businesses of all sizes should implement, enforce and regularly test the following preventative measures:
 
Credential hygiene: Practicing good credential hygiene can help prevent brute force attacks, mitigate the effects of credential theft and reduce the risk of unauthorized network access.

Principle of least privilege: All organizations should adhere to the principle of least privilege, a security concept in which users, programs and processes are given only the bare minimum privileges necessary to perform their tasks.

Employee training: Because ransomware frequently spreads through user-initiated actions, companies should provide regular cybersecurity training with an emphasis on phishing, malicious email attachments and other social engineering tactics.

Multi-factor authentication (MFA): MFA should be made mandatory wherever possible to reduce the risk of unauthorized access.

Review Active Directory: Organizations should regularly review the Active Directory (AD) to locate and close existing backdoors such as compromised service accounts, which often have administrative privileges and are a popular target for attackers who wish to obtain credentials.

Network segregation: Effective network segregation is crucial for containing incidents and minimizing disruption to the wider business.

Secure remote access: As RDP is an extremely popular attack vector, organizations must take steps to secure remote access (or disable it if it is not required). Remote access should only be available via certain networks or MFA-enabled VPN, and limited only to users who require it for their work.

Avoid BYOD: Implementing and strictly enforcing security protocols on employees’ personal devices is extremely challenging. Ideally, companies should provide dedicated devices and hardware and discourage employees from using personal devices for work-related tasks.

PowerShell: PowerShell is one of the most common tools used by ransomware gangs to move laterally within a target network and should be uninstalled if possible. If PowerShell is required, it must be very closely monitored via endpoint detection and response systems. Administrators should be aware of every single PowerShell script that is running on their endpoints.

Cybersecurity insurance: Organizations should consider cybersecurity insurance to help mitigate the impact of a ransomware incident. Cybersecurity insurance can be particularly beneficial for MSPs, which are often responsible for protecting other companies’ data. Some cyber insurance companies lean toward readily paying ransoms, while others prefer to explore other remediation options, so companies should talk to prospective insurers and discuss policies before committing to an insurance provider.

Incident response procedures should be tested regularly to ensure that employees are familiar with security processes and understand exactly what to do in the event of an infection. Testing also helps companies identify and rectify flaws in the response chain. The worst time for a company to try and work out what to do in a ransomware attack is during a real ransomware attack.
 
Conclusion
A proactive approach to ransomware prevention can help companies significantly reduce the risk of infection. In the event of an incident, organizations must have effective response procedures in place to contain the incident, prevent data loss and safely initiate the recovery process.
 
The practices described in this article can help businesses of all sizes mitigate the impact of a ransomware attack. Do note, however, that these procedures should be considered general and non-comprehensive advice. Security requirements can vary significantly and security systems should always be tailored according to industry, regulatory requirements and the company’s unique security needs.

Office for Mac supports the three most recent versions of Apple's macOS. With the release of macOS 10.15 Catalina, Microsoft 365 for Mac and Office 2019 for Mac support macOS 10.15, 10.14, and 10.13
 
Microsoft 365, Office 2019 for Mac:
As of the November 2020 (build 16.43) update for Microsoft 365 for Mac or Office 2019 for Mac, macOS 10.14 Mojave or later is required to receive updates to Word, Excel, PowerPoint, Outlook and OneNote. If you continue with an older version of macOS, your Office apps will still work, but you'll no longer receive any updates including security updates.
 
Upgrading your operating system to macOS 10.14 or later will allow Office updates to be delivered for your apps. Note that new installs of Microsoft 365 for Mac or Office 2019 for Mac will also require macOS 10.14 or later.
 
Microsoft 365, Office 2016 for Mac:
Support for Office 2016 for Mac will end on October 13, 2020. All your Office 2016 apps will continue to function—they won't disappear from your Mac, nor will you lose any data. Learn what Office 2016 for Mac end of support means for you
 
Word, Excel, PowerPoint, Outlook, and OneNote will install and run on OS X 10.10 Yosemite and later.
 
For the best experience with 10.15 Catalina, be sure to keep your Office apps up-to-date. If the version of Office installed on your Mac is earlier than 16.16, and you are not being offered updates, you can download the latest Office for Mac suite installer. See What version of Office am I using?.