Windows Vista Security basics - Spyware FAQ - How can I prevent spyware from infecting my computer?

Run up-to-date antispyware software. Windows Defender, which ships with this version of Windows, helps prevent malicious software, spyware, and other potentially unwanted software or adware from installing itself or running on your computer. It can automatically find and remove malicious software that might already be installed.

Keep your computer up to date. Microsoft often releases security updates to help prevent spyware from being installed without your knowledge. Most new antivirus programs have spyware protection, and should be kept up to date as well. We recommend that you turn on Windows automatic updating, and that you update your spyware and antivirus programs regularly. For more information, see Get security updates for Windows and Using Windows Defender.

Review license agreements before installing software. When you visit websites, do not automatically agree to download anything the site offers. If you download free software, such as file sharing programs or screen savers, read the license agreement carefully. Look for clauses where you must accept advertising and pop-ups from the company, or that the software will send certain information back to the software publisher. For more information, go to the Windows Defender website.