What stages does the Vista Upgrade Prank go through?

Vista Upgrade Prank progresses through four stages to build up the prank:

• Stage 1 -- A fake Windows Update screen appears, suggesting an upgrade is available
• Stage 2 -- A Vista Upgrade Advisor scans your system for "compatibility"
• Stage 3 -- A flashy simulated upgrade process runs for about 30 seconds with icons and progress indicators
• Stage 4 -- A fake Vista desktop appears, complete with a startup sound, but the desktop is actually a Mac OS X desktop with some Windows elements mixed in