Making a bootable DOS partition

If you plan on regularly flashing Bioses, it is a good idea to create a new HDD partition with DOS on it. The advantage is that you have more storage available, that the boot times are considerably faster and that you do not have to start searching for your floppy/CD/USB stick every time you need it.

Harddisks are split up in so called partitions, which create logical disk drives with their assigned letters. Even if you have only one C: drive, you have one big partition spanning over the whole harddisk. Unfortunately, there is no standard way to make an existing partition smaller, to accomodate space for a new partition. However, 3rd party utilities like Partition Magic or BootIt NG can do it.

In order to create a new partition you must have unallocated space of the size for the new partition.

To create a new partition, either go to Disk Management (Control Panel -> Administrative Tools -> Computer Management) in Windows or use the fdisk utility under DOS.



The new partition has to be created as primary, a good size is 32-64 MB. Next, you format the disk with the FAT filesystem (do not use NTFS).

Once you got the partition created and formatted, you somehow have to get the system files onto it.

[add text here how to get an operating system on the partition]

Booting from the Partition

Now with your bootable partition ready, you probably want it listed in the Windows 2000/XP boot menu. You do this by using a Windows command-line tool called BootPart.

Run it without any arguments and it will display a list of partitions on your system:



Find the right partition number in the output, in our case 2. Add it to the boot menu by typing:
bootpart partition_number image_filename displayed_name_in_bootmenu

The image filename is a file in which bootpart stores the bootsector of the partition. I like to use C:\boot.dos. So for our example we would type:
bootpart 2 c:\boot.dos DOS



I find the boot menu's default delay of 30 seconds annoying for day to day usage. That's why I set the timeout to 1 or 2 seconds (System Properties -> Advanced -> Startup & Recovery -> Settings -> Time to display the list of operating systems).
Whenever I need to boot into DOS, I press the down cursor key quickly before the boot menu comes up. Now the cursor moves down one option and the timout is stopped, so the menu is shown and I can select whatever I want to boot.