Another way to access the viewer is by going to START menu >> Run, type eventvwr.msc and pressing ENTER (works in all flavors).
To make the tool easier to access In XP, you can right click on the START button >> Properties >>> Customize >> Advanced tab, then scroll down until you see System Administrative Tools and check 'Display on the all programs menu'.
Now that you know the system error codes, you can uses the resources below to find out what they mean.
This Microsoft TechNet link allows you to enter your event information and get the details and possible fixes to correct the error.
Events and Errors Message Center
Additional information on system error codes can be found at this MSDN site: System Error Codes.