How to Reinstall Windows Defender on Vista

By Eric Hammer

Windows Defender is a feature that Microsoft introduced into Windows with the advent of Windows Vista. It is a service which provides some basic security protection, including all kinds of security threats and pop-ups on the Internet. The software is included and automatically enabled with Windows Vista, however, some people have uninstalled it because they initially thought it was too annoying.

Things You'll Need

  • A computer running Windows Vista and an Internet connection

Reinstall Windows Defender

Step 1

Turn on your computer and click the “Start” button.

Step 2

Click “Internet Explorer.”

Step 3

Type the following into the “Address bar” for “Internet Explorer":

Step 4

Click “Get it now.”

Step 5

Click “Download.” Internet Explorer will ask you if you want to run or save the program. Click “Run.” Wait for the software to finish downloading.

Step 6

You will be asked if you want to run this software. Click “Run.” Follow the on-screen prompts to complete installation of Windows Defender. When it finishes installing, click "Finish."

Step 7

Reboot your computer. Windows Defender will now be running.

Tips & Warnings

  • If you are having a problem with a current version of Windows Defender, you may need to uninstall it before you re-install it. See the reference page for how to do this.
  • As a general rule, Windows Defender should always remain installed on your computer. Removing it could expose your computer to dangerous security threats from the Internet.