To keep your system stable you should always allow the various software programs you have to update to a new release version when available. Many people do not allow the version installed to update, often because they don't trust the message is genuine. It is simple, go to the manufacturers’ website or simply type it into a search engine ("product name" update) and you can easily find out if there is a valid update or a hoax. Some programs offer free updates but not an automated service to do this, so you have to look for the version yourself. Often in the Tools or Help options in the programs toolbar there will be a "check for Updates" button. You should check if there are updated versions of all your software as this ensures the greatest compatibility with your Operating System and things like Internet Browsers and Browser Helper Objects, add-ins and the like. Often a program will crash not because it is broken, but because it cannot communicate with another program or service it needs to use to get a particular feature or function to work. A simple check once a month to see if there are any updates, and more importantly any security fixes, will go some way to ensuring system wide stability. You should always allow your Anti Virus program to update on a regular basis, the virus threats change often and your AV vendor will post updates often on a daily basis in an effort to keep you protected at all times. It goes without saying that you should ensure Windows is up to date as well. There is now a Service Pack release for Windows 7 (released on the 22nd of Feb), a new install is now likely to entail over 100 updates already and a rounding up to a single service pack was becoming necessary.
Below is a list of some of the non Windows updates available, the list of course is endless, but this should go some way to helping you find some of the more popular updates available.
Internet Explorer 9 is now released, called the Release Candidate (not the Beta version) and is available here
It is available in 32 or 64 bit for Windows Vista, Windows 7 or Windows Server 2008 and in various languages (not just English) but note that this edition of IE9 is unavailable for Windows XP and apparently will remain so.
For the latest version of Firefox, the second most popular Internet browser, the download is here
there is also a Beta version of Firefox 4 (I have been using this for some time and it works well on my Windows 7 machine)
Or if you prefer then there is the latest version of Google Chrome here
There is also a new update for Acrobat Reader, this has now been available for a few weeks and can be found here
On the same website you will find updates for Flash Player
and an updated version of Shockwave
You should also download and install the latest version of JAVA if has not automatically done so
If you don't want Windows Mail and don't have Outlook (from Microsoft’s Office Suite) then you could try Thunderbird (from Mozilla the makers of Firefox) on this page you will find the downloads for Windows, Mac and Linux in various languages here
For an alternative to Microsoft Office then use Open Office, this is a free to use piece of software that will read all Office files and is capable of saving to Office compatible file versions as well.
For the fun things there is Google Earth now in a 3D format available for XP, Vista Windows 7 most Mac systems and Linux and the download is here
The latest version of Windows Live (now called Essentials) has been around for a while and will update older versions of Messenger and Mail in particular giving greater compatibility and extra features
Yahoo Messenger also has a new version available, it is a Beta Test version but it has remained stable on my machine (I use it every day) since installation and is an improvement on the current version 10
http://uk.messenger.yahoo.com/download/ (if you want to install the current version)