I'm assuming your asking about Microsoft Windows and possibly Microsoft Windows applications from Microsoft. If you run Windows Explore everything below should work correctly, If you're running Firefox they usually all run on the latest FF releases. If you have trouble with Firefox go to
https://addons.mozilla.org/en-US/firefox/addon/1419
and download and install ietab. restart FF and open these links in an ietab and they'll work just fine. If you want to know what version your running of most applications on your system, go to.
http://www.belarc.com/free_download.html
Download and run the Belarc Advisor.
This is the main Microsoft update site. It updates both operating systems & Microsoft Office products.
http://www.update.microsoft.com/microsoftupdate/v6/default.aspx?ln=en-us
However, it does not include all updates for Microsoft Office products. Fior these you can go here.
http://office.microsoft.com/en-us/downloads/default.aspx
If you just want catalog of updates for the various Offiice, go here.
http://office.microsoft.com/en-us/downloads/CD010200271033.aspx
For Windows Vista, go here.
http://www.microsoft.com/windows/products/windowsvista/default.aspx
For WindowsXP, go here
http://www.microsoft.com/windows/products/windowsxp/default.mspx
If you've never been to any of these sites before you'll be told you have to download software to either/or install update to the updater. With one note of caution say yes to everything. The Microsoft Office updater wants to download, install and run several ActiveX scripts and controls. By default these are turned off. So, unless you have changed your settings for the Internet security zone and if you don't know what these are, just say no and they'll install a version that doesn't require them.
--t