★ “长 Simplified OS Architecture ￥斗 ★★ System support Service User Environment processesprocesses applications subsystems User Subsystem DLLS Mode Kemel M ode Executive Windowin Kemel Device drivers and graphics Hardware Abstraction Layer (HAL4 System support processes Service processes User applications Environment subsystems Subsystem DLLs Executive Kernel Device drivers Hardware Abstraction Layer (HAL) Windowing and graphics User Mode Kernel Mode Simplified OS Architecture