Windows Boot Process 🪟
How Windows Boots (Power Button → Login Screen)
This page visually explains how Windows starts, step by step. You will see where control moves and which files are loaded from UEFI all the way to the final login screen.
Hardware
Firmware
Boot Loader
Kernel
Operating System
User
High-level Windows boot flow
Before the animation, here is the logical order:
- ⚡ Power button is pressed
- 🧠 UEFI firmware runs from motherboard
- 🚀 Windows Boot Manager starts from ESP
- 📋 Boot Configuration Data (BCD) is read
- 📦 Windows OS Loader loads kernel files
- ⚙️ Kernel takes control
- 🧑🔧 System services start
- 😊 Login screen appears
Interactive Windows Boot Timeline (Disk → RAM)
Drag the slider or press Auto. Watch how Windows loads files from the EFI System Partition and Windows partition into RAM.
Key learning points
- UEFI does not load Windows directly
- Boot Manager lives in the EFI System Partition (ESP)
- The kernel (
ntoskrnl.exe) is loaded before login - Once the kernel runs, firmware and boot loader are finished
- Everything you see after login runs on top of the kernel