There are a few areas in Windows 7 you need to pay attention to.
Action Center, the home base for your PC’s security. The Action Center in Windows 7 gives you a view of all your PC’s security and maintenance features. Inside Action Center, you can make sure your Windows Firewall is on, your antivirus software is up to date and that your PC is set to install updates automatically.
User Account Control, the security feature that prompts you for permission to install or open programs. If you are your computer’s administrator (in most cases you are), you can click Yes to continue. If you are not an administrator, someone with an administrator account on the computer will have to enter their password for you to continue.
Windows Update. You can set Windows to automatically install “important” and “recommended” updates or to install important updates only. Important updates are for more critical security and reliability issues and recommended updates address noncritical problems.
Windows Firewall, an easy feature to turn on or off and can help prevent hackers and worms from slithering into your computer through a network or the Internet. A firewall can also help stop your computer from sending malicious software to other computers.
Windows Defender, an antispyware software that’s included with Windows 7, runs automatically when it is turned on. Spyware is any unwanted or potentially harmful software that can be installed on your computer without your knowledge any time you connect to the Internet. It can also infect your computer when you install programs using a CD or DVD.