In Windows XP, for most of the events Event Viewer would add at the end the following sentence:
“For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.”
If one clicks on this link, another window will open with information that will be submitted to the site. The main problem is that in 99% of the cases, there is no additional information listed on that web page. The following registry modification will redirect all the requests to http://www.eventid.net/eventviewer.asp. This page will take the event id and the source and redirect the request to the www.eventid.net search engine. The EventID.net website is much more likely to have useful information than the default Microsoft page.
You can download the registry hack (for Windows XP only) here: eventviewer.reg