I get pop-up ads all the time. Some unwanted software will flood your computer with pop-up ads that aren't related to the Web site you're visiting. These ads are often for adult or other objectionable Web sites. If you see pop-up ads as soon as you turn on your computer or when you're not even browsing the Web, you may have spyware or other unwanted software on your computer.
 

My settings have changed. Some unwanted software has the ability to change your home page or search page settings. This means that the page that opens first when you start your Internet browser or the page that appears when you select "search" may be pages that you do not recognize. Even if you know how to adjust these settings, you may find that they revert back every time you restart your computer.
 

My Web browser contains software/programs that I don't remember downloading. You may notice new programs that have been installed or that you don't recognize.  Spyware and other unwanted software can also add additional toolbars to your Web browser that you don't want or need. Even if you know how to remove these toolbars, they may return each time you restart your computer. 
 

My computer seems sluggish. Spyware and other unwanted software are not designed to be efficient. The resources these programs use to track your activities and deliver advertisements can slow down your computer and errors in the software can make your computer crash. If you notice a sudden increase in the number of times a certain program crashes, or if your computer is slower than normal at performing routine tasks, you may have spyware on your machine.

Don't click on pop up ads.
 

Only download programs from Web sites you trust. If you're not sure whether to trust a program you are considering downloading, ask a knowledgeable friend or enter the name of the program into your favorite search engine to see if anyone else has reported that it contains spyware.
 

Never click "agree" or "OK" to close a window. Instead, click the red "x" in the corner of the window or press the Alt + F4 buttons on your keyboard to close a window.
 

Be wary of popular "free" music and movie file-sharing programs, and be sure you clearly understand all of the software packaged with those programs.
 

Install Anti-Spyware Software, and keep it up to date.
 

Update your Operating System and your web browser.
 

Read all security warnings, license agreements, and privacy statements associated with any software you download.