I have been using Secunia 3.0 Beta for some time and recommend it to all PC users. It is free for personal use. I suggest you use to keep your PC software up to date.
Here is the message they sent:
We just wanted to let you know that Secunia has released the final version
of Secunia PSI 3.0, featuring a new and simplified interface, more
automated updates, multiple languages (English, German, Spanish, French
and Danish), as well as a lot of other improvements that we hope you will
like.
You can download the new version here (it is of course still available for
free):
http://secunia.com/vulnerability_scanning/personal/
And if you want a quick product tour see the PSI video on Youtube:
https://www.youtube.com/watch?v=iUmaLmO0gx0&list=UU8EGaYoGIGlMAbfeJrS_0OQ&index=2&feature=plcp
If interested you can also read the full press release here:
http://secunia.com/company/blog_news/news/319/