Startup Phases for x86-based Systems
The Windows XP Professional startup process closely resembles that of Microsoft® Windows NT® version 4.0 and Microsoft® Windows® 2000, but significantly differs from Microsoft® MSDOS®, Microsoft® Windows® 95, Microsoft® Windows® 98, and Microsoft® Windows® Millennium Edition (Windows Me).
All computers running Windows XP Professional share the same startup sequence:
Power-on self test (POST) phase
Initial startup phase
Boot loader phase
Detect and configure hardware phase
Kernel loading phase
The preceding startup sequence applies to systems started or restarted after a normal shutdown, and does not apply when you bring your computer out of hibernation or standby.