Unwanted software are programs that alter the Windows experience without your consent or control. This can take the form of modified browsing experience, lack of control over downloads and installation, misleading messages, or unauthorized changes to Windows settings.
How unwanted software works
Unwanted software can be introduced when a user searches for and downloads applications from the internet. Some applications are software bundlers, which means that they are packed with other applications. As a result, other programs can be inadvertently installed when the original application is downloaded.
Here are some indications of unwanted software:
There are programs that you did not install and that may be difficult to uninstall
Browser features or settings have changed, and you can’t view or modify them
There are excessive messages about your device's health or about files and programs
There are ads that cannot be easily closed
Some indicators are harder to recognize because they are less disruptive, but are still unwanted. For example, unwanted software can modify web pages to display specific ads, monitor browsing activities, or remove control of the browser.
Microsoft uses an extensive evaluation criteria to identify unwanted software.
How to protect against unwanted software
To prevent unwanted software infection, download software only from official websites, or from the Microsoft Store. Be wary of downloading software from third-party sites.
Use Microsoft Edge when browsing the internet. Microsoft Edge includes additional protections that effectively block browser modifiers that can change your browser settings. Microsoft Edge also blocks known websites hosting unwanted software using SmartScreen (also used by Internet Explorer).
Enable Windows Defender AV in Windows 10. It provides real-time protection against threats and detects and removes known unwanted software.
Download Microsoft Security Essentials for real-time protection in Windows 7 or Windows Vista.
For more general tips, see prevent malware infection.
What should I do if my device is infected?
If you suspect that you have unwanted software, you can submit files for analysis.
Some unwanted software adds uninstallation entries, which means that you can remove them using Settings.
- Select the Start button
- Go to Settings > Apps > Apps & features.
- Select the app you want to uninstall, then click Uninstall.
If you only recently noticed symptoms of unwanted software infection, consider sorting the apps by install date, and then uninstall the most recent apps that you did not install.
You may also need to remove browser add-ons in your browsers, such as Internet Explorer, Firefox, or Chrome.
In case threat removal is unsuccessful, read about troubleshooting malware detection and removal problems.