LOGO.SYS

The startup screen from Windows 95 build 490

LOGO.SYS is a core system file used by Windows 9x operating systems to display its boot-up message.

It is present and used in the Windows 95, Windows 98, Windows 98 SE and Windows ME products. It is not present in the Windows NT family of operating systems, such as Windows XP.

There are three variants of the file:

• LOGO.SYS: the "Starting Windows" message, with the Windows logo. The file is located in the root directory of the boot drive. This is usually C:\, but with drive compression, like DriveSpace, this is the host drive (often H:\). The default LOGO.SYS file is also stored in IO.SYS and used by MS-DOS during startup if LOGO.SYS could not be found. The display of the logo can be disabled by adding a LOGO=0 setting to the Options section in the MS-DOS 7 configuration file MSDOS.SYS.
• LOGOW.SYS: the "Please wait while Windows is shutting down" message. The file is located in the Windows directory, which by default is C:\WINDOWS. The Windows logo is shown only in Windows 95 and 98. No error will be shown if the file cannot be found.
• LOGOS.SYS: the "It is now safe to turn off your computer" message. The file is located in the Windows directory. This message is displayed when Windows has successfully shut down to MS-DOS but is not configured to return to the prompt (COMMAND.COM) again. On systems with proper ACPI support and ATX power supply, the PC may power down instead. If the file cannot be found, the same message is displayed in text mode. No error will be shown if the file cannot be found.

LOGO.SYS is in fact an RGB-encoded Windows bitmap file with a resolution of exactly 320×400 pixels at 256 colors. Windows displays the image in the resolution of the standard VGA text mode (BIOS 13h mode), which equals a resolution of 720×400 pixels, so that the image is stretched to a standard 4:3 aspect ratio (given a standard 4:3 computer monitor typical at the time).

For LOGO.SYS or the equivalent embedded image in IO.SYS, Windows will also animate the image's color information using palette rotation; the image is static, but may have the illusion of movement as colors are changed.

The files may be opened and edited using image editing tools such as MS Paint, and the contents replaced with user-selected pictures.

References

• Replace the Ugly Startup and Shutdown Screens (archived version)

External links

• Rubenking, Neil (2000-05-23). "Windows Start-Up and Shutdown Screens". PC Magazine (Ziff Davis) 19: 123–124.
• Schnurer, Georg (1995). "Logo-lei". c't (in German) (Heise) (11): 332.
• MSKB (de): Individuelle Bilder bei Start und Beenden von Windows 98 anzeigen