Keeping all these applications up to date with all security patches and bug fixes is a massive task, but this piece of software can make the task manageable for most people.
When installed, Secunia runs a scan and thereafter inform you about any upgrades available to your installed software. You can then use their quick and easy wizards to update your software one by one, or you can do this manually by entering each application and use their own builtin software updater.
For novice users Secunia offer a "Simple" mode. Running this will advice you wrt. the majority of threats.If you however are extremely security focused, then go to advanced mode and follow the instructions there as well to ensure highest level of security.
Secunia will load at the startup and run in a minimized mode on your taskbar down in the right hand corner of your Windows PC. You can therefore access the program itself by doubleclicking the little red symbol. Anytime there are changes you will therefore see a little message appearing in your right hand bottom corner notifying you of changes.
Home users can download Secunia PSI for free from the Secunia website on: http://secunia.com/vulnerability_scanning/personal/
An external review of Secunia PSI can be found on: http://tinyurl.com/yaoksn3