UseBIOSToBoot Entry in Unattend.txt Is Enabled Regardless of the Set Value (282191)

SUMMARY

When you create an unattended answer file, you can use an entry called UseBIOSToBoot in the [data] section. With this entry, Setup can bypass the boot controller's miniport driver and use INT 13 BIOS calls to boot into the operating system.

If this entry is listed in the answer file, it will be used regardless of the value that is set for it. For example, an entry such as UseBIOSToBoot=0 would not disable the use of this feature. If this entry is not present, Setup uses logic to determine whether or not to use the BIOS to start Windows XP.

MORE INFORMATION

Setup will always use the basic input/output system (BIOS) to start if you include UseBIOSToBoot in your Unattend.txt file, regardless of the assigned value. You may create a "master" answer file that contains all of the entries that are available in an Unattend.txt file, and set the values of the unwanted options to Option=0 or Option=No; however, this method may produce unexpected results.

If you use UseBIOSToBoot on a computer that does not support INT 13 extensions, the computer could become unbootable if the boot files and kernel are ever located outside of the 1024 cylinder limit of data that is accessible by way of INT 13. This can happen unexpectedly through the use of disk defragmenters or by the application of hotfixes and service packs.

For additional information about the limitations of booting by way of INT 13, click the article number below to view the article in the Microsoft Knowledge Base:

224526 Windows NT 4.0 Supports Maximum of 7.8-GB System Partition