What Really Happens When a Computer Starts

So you want to know what really goes on when you turn on your computer.

Your computer follows a boot process that loads Windows XP, called the boot or startup sequence. This process loads all of the operating system files so you can actually use Windows XP. Here’s what happens:
1. When you first turn on your computer, a power-on self test (POST) process occurs. Your computer checks its hardware and memory and then begins to load your operating system.
2. Windows XP has a database of information called the Registry where information about your computer is kept. The Registry is loaded first so it can be read in order to boot Windows XP.
3. Next, Windows loads a file called System.ini. The System.ini file is used to load older system configuration information.
4. Next, Kernel32.dll is loaded. Kernel32.dll is the main operating system code used by Windows XP.
5. After Kernel32.dll is loaded, Gdi.exe and Gdi32.exe are loaded. These files give you the graphical Windows user interface.
6. Next, User.exe and User32.exe are loaded. These files provide code necessary to manage the user interface, including your windows.
7. Resources and Fonts load next.
8. Then, Win.ini is loaded, which provides older system programs and user support.
9. Next, the Windows shell loads, which is your basic graphical interface settings, and policies for your computer are loaded as well.
10. The desktop components are loaded next.
11. Next, a logon dialog box appears. Once you provide a valid username and password, the logon process begins. If you are connected to a network, any appropriate network policies are loaded.
12. Finally, all of the final information from any policies are loaded, and you see your desktop. The boot process is fast and efficient, and is more stable than ever before in Windows XP.