Easter Eggs (Definition) - A hidden message or feature in an application. This guide covers unknown features in Windows XP, some are carryovers from older versions of Windows, all were tested in Windows XP only. 
Windows XP is still supported by Microsoft through April 8, 2014.Notes - This is not a performance related guide, use the Optimize XP Guide to improve system performance and the Diagnose XP Guide to troubleshoot a system problem. Technically, Windows XP does not include any easter eggs - "to supply certain government agencies with software, Microsoft can't include undocumented features, including Easter eggs". - WindowsITPro - Microsoft
