A secure computer operating system means that your data and information are protected in the case of computer theft or other fraudulent attempts to log on to the computer. Setting a password on the computer is important whether using a Microsoft or Mac operating system and is one of the safest ways to protect yourself at home or school or in the workplace.
Determine which operating system your computer is running if you don't already know. Some versions of operating systems have slightly different methods of setting passwords for the computer. In Microsoft Windows operating systems, this information can usually be found by opening the "System Properties" dialog box. Mac users can typically find the Mac operating system version by going to the "About this Mac" box found under the Apple menu.
Open the operating system's user account and log on authentication preferences. If using a Microsoft Windows platform like XP or Vista, double-click the "User Accounts" icon in the Control Panel. If using a Mac operating system version 10.2 or later, the user account preferences can usually be opened by clicking on "Accounts" in the System Preferences box from the Apple menu.
Select the computer user account for which you want to set a password. If there is only one user account on the computer, this should be labeled as "Administrator." In a Microsoft Windows operating system, click once on the user account's name or icon to view a list of options for changing the user's account. On a Mac operating system version 10.2 or later, click on the user name in the "Accounts" box.
Create and set the password for the computer user account. In the "User Accounts" list of options in a Microsoft Windows operating system, click the "Create a Password" option, type in your preferred password and click "Create a Password" to set it. On a Mac in the user's account preferences, click on the "Reset" or "Change a Password" option, type in the new password and finish the process by clicking the "Reset" or "Change a Password" option again. General guidelines for creating a secure password include avoiding common words like "apple" or "computer," but using a combination of letters and numbers.