Boot screen

A boot screen is often displayed by an operating system or other software to visually indicate its initial loading process. Depending on the software, the screen may include version information, a definite or indefinite progress indicator, or status messages. Many boot screens also feature the branding of the loaded software, its developer and/or distributor.

16-bit Windows
In early versions of Windows, the boot screen is a device-dependent standalone module which handles the logo drawing and animation. The logo module stored in a  file on setup disks gets combined during installation with the device independent   component to form the   launcher, which allowed OEMs to ship their own logo code if desired. The first known build to use a boot screen was Windows 1.0 Beta Release, which features a merging Microsoft logo and version information. This screen remained virtually unchanged for retail releases until Windows 1.04, when the Microsoft logo was updated to the 1987 logo.

In Windows 2.0, the logo bitmap and text was separated to a separate common  file, which still gets combined with the other parts to form. The same system remained in place for Windows 3.0 and later 16-bit versions, although the boot screen itself has been changed to a graphical still image stored in the RLE format.

Windows 9x
Windows 95 introduced a new boot screen, which runs in the VGA 256-color mode and changes reserved entries in the end of the color palette in runtime in order to show an animation. In most builds, the main boot logo is contained in  in a compressed form, although it is possible to use a custom logo by saving it as   in the boot drive root directory. The same method can also be used for the "shutting down" and "safe to shutdown"  screens. In all cases, the logo file must be 320x400 pixels in size and should be saved in the RLE format.

Early builds used an animation reminiscent of the "Flying Windows" screensaver, with Windows logos randomly lighting up in a random color all over the screen. This was accomplished by the logo bitmap including a number of the Windows flags, each using a different color from the reserved area. Normally, the reserved entries would be set to black, with the boot animation code setting them to a color in order to accomplish the effect.

The animation was changed as of build 337 to merely rotate the reserved palette entries, which was used for the scrolling arrows effect in later beta builds as well as the rotating gradient bar in the final builds and the breathing Windows logo animation used for the first boot screen in Windows 95 and early Windows 98 builds.

The boot screen was completely missing from Windows Me until Beta 2, due to the changes made to the real mode MS-DOS subsystem.

Windows NT
Build 196, the only available build that does not use the conventional boot process, shows a text screen with dark text on light gray background at boot. Unlike any later builds, this boot screen appears to be mostly handled by the boot loader, which prints its version information on screen as it loads the kernel binary. The screen is then cleared and replaced by a line full of equal signs when the kernel starts executing. It is also possible to patch the boot loader to display verbose information about the loaded kernel image at boot.

The boot screen was reimplemented in the kernel itself for the October 1991 build. The color scheme was changed to white text on a blue background as a part of this change, which matches the also newly introduced blue screen of death and was picked to match the MIPS firmware display as well as the default color scheme of the SlickEdit text editor used by many NT developers. The boot screen now shows the OS version and memory amount information and also doubles as a console for early user mode processes. On IBM-compatible systems, the boot screen originally used a 25 line text mode, although it was later changed to 50 lines as of build 475. Windows NT 3.5 later updated the boot screen to show the number of processors at all times, as it was previously only shown when using the multi-processor kernel.

The last known build to include support for operating a text mode display is Windows 2000 build 1814.1, although it has been disabled by default since the introduction of the  driver and had to be enabled by using the   kernel switch; in following builds the switch disables the boot screen altogether and only displays a blank screen with a blinking cursor. The boot-time text console itself was kept even after Windows 2000 introduced a graphical boot screen, albeit reimplemented in graphics mode, and is used whenever an early boot process wants to print something to the screen. In Windows 7 and older, the  kernel switch disables the boot animation altogether and prints the version and system information to the console similarly to Windows NT 4.0.

Windows 2000 to Vista
Build 1796 is the first known build to include the  driver for boot-time graphics. This allowed for the implementation of a new, graphical boot screen, which runs in 640x480 resolution with 16 colors and features the operating system logo together with a gradient bar and a determinate progress bar showing the boot process progressing. Later builds polished the boot process by introducing a rotating animation for the gradient bar, adding a separate design for the boot-time text console or by using different graphics for the Professional and Server editions. Originally, the boot screen rendered in a smaller centered window surrounded by a color fill, although it was later redesigned to cover the full screen.

The boot loader in Windows Neptune appears to have been extended with code to render the boot screen when resuming the computer from hibernation or when booting with the Fast Startup feature enabled, replacing the text mode progress screen shown by both older and newer builds. The feature is clearly unfinished, as pressing Esc pauses the process but does not show any interface allowing the user to choose the next course of action. The rotating bar animation is not implemented either.

The boot animation design further evolved during the development of Windows XP. The light background of the Windows 2000 boot screen was replaced by black, assumably to hide the screen being slowly drawn in the beginning. The determinate progress bar was also removed, although the code for reporting progress is still present within the startup code. The first new design included in Beta 1 builds featured a white Whistler logo, together with a animated bar full of dots. This was replaced in Beta 2 builds by a design that also featured a white Whistler logo, albeit monochromatic, with a breathing animation of four color bars corresponding to the colors of the Windows logo. The Beta 2 design has two variants, one of which features the older Windows logo while the other features the new logo.

The boot screen was again updated after Beta 2 to reflect the introduction of the Windows XP name. The original design featured the new plastic Windows XP logo with a breathing "loading..." label underneath, although it was soon replaced by the final rotating bars animation. Edition branding and different animation colors were initially used to distinguish each edition, however, all editions ended up using the exact same boot screen since Service Pack 2. The overall Windows XP boot screen design remained in use for Windows Server 2003 and Windows Vista, albeit with different branding and updated design of the animation elements.

Windows 7
In Windows 7 build 6469, a hidden boot screen can be enabled by opening System Configuration Utility, clicking on the Boot tab and checking the "No GUI Boot" box. This boot screen had the Windows logo but, with a large "7", referencing the Operating System's code name. The GUI boot screen in this build is unchanged. In Windows 7 build 6519, the Windows Vista boot screen was changed to an animated version of the aurora background where a loading animation at the bottom acts as a progress bar. In Windows 7 build 6730, the boot screen was modified again. This time, it uses the aurora background from Windows Vista's (SP1+) setup and at the center of the screen, it says, "Starting Windows". In Windows 7 build 6780, the boot screen was modified to remove the aurora background and introduces a redesigned progress bar that appears with the Starting Windows text appearing on top of the progress bar. In Windows 7 build 6941, the progress bar was completely replaced with an animation of the Windows logo forming on the screen.

Windows 8-11/Server 2012-2022
The Windows 7 boot screen got replaced in build 7973 (fbl_core1_kernel_npc) with the image of a betta fish, spinning circles and "Welcome". The latter two grew in size in build 7997. Further changes are:
 * The replacement with "Windows Developer Preview" and the removal of the "Welcome" text
 * The readdition of the betta fish as two-dimensional
 * The re-replacement with "Windows®"

The final iteration of the boot screen of Windows 8, 8.1, 10 as well as their server counterparts can be firstly seen in Windows 8 build 8513. It shows the Windows flag from 2012 and has been updated in Windows 11.

A new boot spinner was introduced in Manganese build 19587 but it was disabled by default. It would later be enabled by default starting with Nickel build 22449.

macOS
Mac OS X Server 1.x shows the boot stages of the Mach kernel inside of a window.

Earlier versions show the Apple logo with spinning lines on white background.

Current versions show the Apple logo with a progress bar on either dark or white background.

Linux
x86 versions show: Uncompressing Linux... Ok, booting the kernel.

while amd64 versions show instead: Decompressing Linux... Booting the kernel.

Ubuntu
Earlier versions displayed a progress bar which at first looped then gone full.

Starting with Ubuntu 10.04, the boot screen contains four or five points which at first glow up then gone back. On lower configurations, a fallback boot screen is displayed, where the Ubuntu logo is replaced with "Ubuntu YY.MM" written in kernel-mode font.

Spinning circles were introduced alongside with UEFI support in Ubuntu 20.04, with the Ubuntu logo at the bottom and (optionally) an OEM logo at the top.

Zorin OS
The boot screen is very minimalistic, only featuring the logo. Starting with Zorin OS 16, it can also display an OEM logo at the top.

Fedora
Similar to Ubuntu, with a spinning circle in the middle, (optionally) an OEM logo at the top and the Fedora logo at the bottom of the screen.

ReactOS
The boot screen is similar to Windows XP/Server 2003.

Windows 7 and Windows Server 2008 R2
NOTE: Server 2008 R2 continued to use the boot screen from its predecessor starting with 7000.