You are currently offline, waiting for your internet to reconnect
Questions about Windows 10? Click here

Explanation of X86 Boot Drive Limitations

This article was previously published under Q154052
This article has been archived. It is offered "as is" and will no longer be updated.
During Setup, Windows NT can only be installed within the first 1,024cylinders of the boot drive. This is due to Interrupt 13 limitations onx86 computers.
When starting an x86 based computer, retrieves and storesInterrupt 13 information. This information is supplied by the computer'sBIOS. Only information for the first two disks in the system is saved. Thisinformation about the drive layout is then passed to the operating systemduring initialization. The amount of space that the operating system filescan use to boot the system is limited in Windows NT to the first 1,024cylinders of disk 0. This means that Ntldr, Boot.ini, and theWindows NT operating system files must be within this boundary.

If the disk controller is using a 32 sector/64 head translation scheme,this boundary will be 1 GB. If the controller uses 63 sector/255 headtranslation, the limit will be 4 GB. If there is a secondary controllerthat does not have BIOS enabled, Windows NT will default to 32 sectors/64heads. In some cases, such as duplexing, this may cause identical drives ondifferent controllers to be interpreted as being slightly different insize.

Article ID: 154052 - Last Review: 02/24/2014 08:25:10 - Revision: 2.1

  • Microsoft Windows NT Workstation 3.5
  • Microsoft Windows NT Workstation 3.51
  • Microsoft Windows NT Workstation 4.0 Developer Edition
  • Microsoft Windows NT Server 3.5
  • Microsoft Windows NT Server 3.51
  • Microsoft Windows NT Server 4.0 Standard Edition
  • kbnosurvey kbarchive kbsetup KB154052