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Windows 9X Boot Sequence

1


After the BIOS performs the POST, and if the PC has a Plug and Play BIOS, Plug and Play devices are configured.

2

The partition table is accessed, and the boot record activates the IO.SYS

3


The Windows 9x boot sequence performs partially in the real mode and then switches to the protected mode. Beginning at this point, the boot sequence performs in the real mode.

4


The MSDOS.SYS is checked for any Windows parameters (such as BootMulti or BootMenu).

5



If all is normal, the message Starting Windows 9X displays or the Windows 9X splash screen is displayed. The system pauses for 2 seconds to wait for a function key to change the boot path.

6

If file compression is in use, DRIVESPACE.BIN loads.

7

The Registry (SYSTEM.DAT) is checked, and if its valid, it loads.

8

Windows 9X performs hardware detection and identifies any new hardware.

9


IO.SYS processes the commands in the CONFIG.SYS and the AUTOEXEC.BAT files, if they exist.

10

The boot sequence switches to the protected mode.

11

WIN.COM executes.

12


The VMM32.VXD file and all virtual device drivers included in the Registry or the SYSTEM.INI file load.

13


Windows 9X core components - Kernel, GDI, and User -- load, along with the Explorer and network support.

14

Any applications in the startup (RunOnce) section of the Registry start.

15

The boot sequence ends.