GRUB4DOS - Fundamentals

For GRUB4DOS device syntax, refer to the GRUB4DOS - Device Allocation/Numbering section of this guide.

During the GRUB4DOS boot process a number of messages are parsed. Due to the speed at which the messages are displayed it is very difficult to read them, which can cause problems identifying at which point the boot process fails in the event of any problems. If grub4dos fails to boot, quickly press the [insert] key whilst its loading to enter debug mode this will display detailed step-by-step startup information and will allow you to identify at which point grub4dos is failing.

Grub4dos has a powerful command line interface, which can be scripted via a configuration file. The configuration file (menu.lst) is automatically loaded if found - to access the command line from a boot menu press the [c] key. Entering commands from the command line is far more flexible than using configuration file entries, and will provide detailed feedback. Although the command line can be intimidating, only a handful of the supported commands are needed to boot the majority of operating systems. The command line is the recommended method for testing new boot options and is essential for troubleshooting problems.

Screenshot of the GRUB4DOS command line (GRUB4DOS version 0.4.6a 2020-03-04) -

The [tab] features is explored in more detail in the GRUB4DOS - Command Line section of this guide.

Document date - 12th April 2023