Patches are software add-ons designed to fix software bugs, including security, in operating systems or applications.

Patching against new security vulnerabilities is critical to protect against malware. Many high-profile threats take advantage of security vulnerabilities, such as Conficker. If your patches are not applied or not up to date, you risk leaving your computer open to hackers.

Many software suppliers routinely release new patches, with Microsoft issuing fixes on the second Tuesday of each month (“Patch Tuesday”), and Adobe issuing quarterly updates to Adobe Reader and Acrobat on the second Tuesday after a quarter begins.

To stay abreast of the latest vulnerabilities and patches, subscribe to vulnerability mailing lists. Most reputable vendors offer such a service. For example, Microsoft security information is available at

Microsoft Windows home users can visit to check their computers for available updates. Apple OS X users can click the Apple logo in the upper-left corner of their desktop and select software Updates.

Organisations should ensure that all computers connecting to their network abide by a defined security policy that includes having the latest security patches in place.