This guide has been created to give you a better understanding of the BOOTWIZ.OSS file. When working with this file (adding an OS menu entry manually, for example), it's necessary to know how to read it. Entering incorrect information can cause OSS to reset the file or render an OS unbootable through OSS.
The BOOTWIZ.OSS file is a standard XML file. The most common encoding format is UTF-8, though ANSI is sometimes used.
A copy of the file being examined in this guide can be downloaded. It may help to have it open in Notepad as you read the guide.
This is what the contents of the file look like. Depending on the number of drives, partitions and operating systems installed, yours may contain a lot more information.
This sample file shows a computer with two hard drives, four partitions and one operating system (Vista).
A more normal file will usually have an OS entry for a floppy drive (if it exists) and bootable CD entries.
The main sections of interest are the <disks> , <partitions> and <oses> sections. These contain the data needed to boot into an OS.
Each drive is assigned a unique ID value by OSS when it is installed or when it rescans the computer and detects new/changed drives. The ID value is located at the beginning of each drive entry:
The real_bios_num value starts at 128 (the booting drive) and increments for each additional drive. Note that the drives are not always listed in order.
The size value is the number of 512 byte sectors that exist on the drive. The size in GB can be calculated using the following formula (where n=size): (((n*512)/1024)/1024)/1024
All detected partitions are listed in this section. In this sample file, there are four. As with the drives, each has a unique ID value assigned to it:
Important values for partitions are listed below:
begin = Starting sector of the partition.
disk = ID of drive on which the partition exists.
fs = File system (format) of partition.
number = Partition table slot number for Primary partitions (1 through 4), or 5 or higher for Logical partitions.
size = Number of 512 byte sectors in the partition. Size in GB can be calculated using the following formula (where n=size): (((n*512)/1024)/1024)/1024
type = Partition type. I won't list them all here, but 7=NTFS and 12 = FAT32.
For example: If I'm looking for the third Primary partition (2nd NTFS partition) on the booting hard drive, the partition ID value would be: 2457113254
Using a screenshot of what Disk Director shows (in Manual Mode) can be very helpful to ensure you're getting the correct ID value.
This section contains all of the OS menu entries, floppy entry and bootable CD entries. Each entry will have a unique ID value. In this sample file, only a Vista entry has been detected and it has the ID value of 3056036235.
Important values for OS entries are listed below:
boot_partition = The partition ID value of the booting partition for this entry. In the case of a Windows OS, this is the partition that would the Active.
icon = Icon used for the entry. Normal values are icon_sys_vista (Vista), icon_sys_win (XP), icon_sys_linux (Linux).
name_template = Name shown in the OSS menu for this entry. If set by OSS, it will often be coded and look like this: %n%l %l(%ll%l). It can be changed to whatever text you want for that entry.
os_type = The OS type for the entry. Normal values are ntvista (Vista), ntxp (XP), linux (Linux).
system_root_identifier = Vista only. Won't exist in manually added entries.
multi = Pre-Vista (boot.ini Windows, like XP) only. May or may not exist in manually added entries.
use_manual_disks_order = If set to 1, this enables the Disk Order feature. This option should not be used with Vista or Windows 7 entries.
write_boot = If 1, the boot sector for the booting partition of this entry will be written when OSS boots it. Normally, this is fine for any automatically detected OS entries and is the default. However, when you manually added an entry, the saved boot sector file won't exist and this option should be disabled (set to 0).
Each OS entry also has a <partitions> section. This section is where the Active and hidden partitions are set. Note that these settings apply only to the OS entry in which they reside.
In this sample file, the Vista entry has the Vista partition (which is also the booting partition) set Active:
If I want to hide the Temp partition, it would look like this: