Adware is more annoying than dangerous, but you’ll still want to avoid it. Here’s how!

Always Use an Anti-Virus

Although adware isn’t technically a virus, most anti-virus suites look for adware in addition to other types of malicious software. Ensure that this program is running and has updated virus definitions whenever you’re using any program that sends and receives data over the Internet, including Web browsers, email clients, chat programs and downloading tools.

You may have to choose between programs to find the best balance between protection and performance — some antivirus programs hog resources and can cause your computer to lag. However, a scanner running quietly in the background can alert you when any email attachment, file download or website is infected, so you can prevent unauthorized access to your computer.

Don’t Download Unknown Files

One of the great things about the Internet is that anything you want is just a download a way. But creators of adware and other malware know this, which is why they’ll create fake files posing at the ones you want. Coincidentally, this is also how some companies track illegal downloads.

Similarly, email hackers will use their victims’ address books to send email attachments to people or use well-known names such as banks and PayPal as a guise for adware, and you might download them if you’re trusting. Verify with your friends before opening any odd attachments and learn to identify legitimate emails. For example, PayPal always uses your name, and you can hover over — not click — on links to see if they actually point to the right site.

Read All Terms and Conditions

Because adware so frequently hitches a ride with software you do actually want, it’s essential that you pay attention to the install program. First, some sites will try to get you to install a special downloader rather than downloading the file directly. Whenever this is the case, opt to download the file directly.

Secondly, look for mentions of tagalong adware, such as browser toolbars, whenever you install new software. You might be surprised how many programs want to change your browser homepage and search engine, too. Simply uncheck those options or click “Cancel” to move to the next part of the installer and get the software you actually want.

You can also install an ad blocker to your browser and instruct your PC to block third-party installations to prevent adware.