Install the latest updates to the software you use, such as your web browser, Microsoft Office, etc. If your software does not automatically download updates for you, check the developer's website to be sure you're running the latest version.
Being aware of what you are doing.
When something isn't going right, to stop and check why it isn't working correctly.
Regularly updating your Anti-Virus definitions.
Regularly scanning your computer for infections.
Keeping your computer up to date with system updates.
Why should I do it?
Keeps your computer functional.
Makes things easier in the long run (preventive maintenance).
Keeps your personal information safe and secure.
May put less stress on your computer and keep it running better, longer.
Ways to be aware:
Look at emails before replying to them. Check the spelling and punctuation for errors. Many times phishing emails will have simple errors that are easy to see.
Be aware of emails asking for personal information, generally a real organization will make you change your password/login yourself, rather than asking you for yours.
If there is a program that pops up on your computer saying that you have viruses, and you did not install that program, then it is a virus. Also be cautious of web-pages that have similar pop-ups that are not part of your computer.
When you visit web-pages, look for the content you intend to find, not what is flashing, or ads on the side.
Some great programs to help you know what is considered safe are Web of Trust and McAfee Site Advisor. These programs let you know if a site is one that is considered safe, or one that is known to cause problems.