[This version of Windows Defender is still in development, so some Help information might be inaccurate or missing.]

How to tell if your computer is infected with spyware

You might have some form of spyware on your computer if:

• You notice new toolbars, links, or favorites that you did not intentionally add to your web browser.
• Your home page, mouse pointer, or search program changes unexpectedly.
• You type the address for a specific website (for example, a search engine), but you are taken to a different website without notice.
• You see pop-up ads, even if you're not on the Internet.
• Your computer suddenly starts running more slowly that it usually does.

There might be spyware on your computer even if you don't see any symptoms. These types of software can collect information about you and your computer without your knowledge or consent. To help protect your privacy and your computer, we recommend that you run Microsoft Windows Defender at all times.

Related Topics

Using Windows Defender

Turn Windows Defender on or off

Remove spyware from your computer