Keeping your computer running in tip-top shape is only going to happen if you protect yourself from hackers, spyware, malware and malicious viruses. You can do that with a free download of Norton 360 Antivirus.
When you download it, you'll get the full version from Symantec, not just some stripped down trial version. Best of all, unlike with most other trials, you don't have to provide any credit card information upfront for the trial. Translation: This won't turn into a paid subscription after 30 if you don't cancel it. At the end of 30 days, if you don't buy the full version, the software simply expires. No fees, no questions asked.
If your computer doesn't have any antivirus software on it, this is a good way to take Norton 360 for a test run before forking over any cash.