This browser is no longer supported.
Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(128, 8%, 22%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EA%3C/text%3E%3C/svg%3E)
On an older system that only supports 28-bit Logical Block Addressing (LBA) (only sees hard drives of 137.4 GB or smaller) and not 48-bit LBA, can I overcome this limitation by formatting a small Windows XP system partition (C:), perhaps 50 MB or less and creating a second partition (D:), the boot partition and installing Windows on this boot partition? Another option would be to format the system partition near the 137.4 GB limit; however, I would prefer to have all of my files, with the exception of the system partition files (ntldr, boot.ini, ntdetect), on one partition, as if it were a single C:\ partition. Also, if I do not plan to dual-boot the system, is 50 MB too large of a system partition or will additional files be placed on this partition, with normal use of the system? What would be an appropriate size for such an XP system partition?
I have been using this system for years; however, now that I have acquired a lot of data, I started getting the dreaded "disk read error occurred" message and I have linked it to the 28-bit LBA limitation. So, I am wondering if I can overcome this by simply creating a small XP system partition and a large XP boot partition (for D:\Windows directories, data directories, etc.), as I do NOT want to rebuild my system, only to see this "disk read error" message, again.
Thank you for your assistance. I look forward to everyone's help.
Thank you.
Locked Question. This question was migrated from the Microsoft Support Community. You can vote on whether it's helpful, but you can't add comments or replies or follow the question.
Hello:
In this circumstance, do others believe that if one partitions such a hard drive into partitions that are less than 137.4 GB in size, that this will keep one from having any 28-bit limitation-based issues, as the older motherboard should be able to see the entire system and boot partitions, even if they are separated?
On Fri, 8 Oct 2010 21:54:16 +0000, Voltron-IU wrote:
On an older system that only supports 28-bit Logical Block Addressing (LBA)(only sees hard drives of 137.4 GB or smaller) and not 48-bit LBA, can Iovercome this limitation by formatting a small Windows XP/system/ partition
No, it's not Windows that only sees partitions up to 137GB, it's the
BIOS that only sees physical hard drives up to 137GB. (But see point
number 2 below, for the Windows involvement).
You need two things to support a drive that large:
(or alternatively, an add-in controller card that does).
Ken Blake (MS MVP)
Some time ago it was reported, in circumstances such as yours, that there was a theoretical posibility of data loss / corruption if a large disk was used with the o/s installed on a small partition, then another partition created from the resulting drive space.
Its also the case that emulation software that enables a large disk to be used when the bios doesnt support it can lead to problems.
Your hw must be very old, and you could be said to be living on borrowed time. I trust you have verified data backups.
This answer has been deleted due to a violation of our Code of Conduct. The answer was manually reported or identified through automated detection before action was taken. Please refer to our Code of Conduct for more information.
Comments have been turned off. Learn more
Hello, Ken:
Thank you for your quick response. I am aware of the points you addressed. My motherboard does not support 48-bit LBA, it only supports 28-bit, which is why my BIOS only sees 137.4 GB of my hard drive. I am using Windows XP Professional, with Service Pack 3. I am not able to use an add-on controller card; so, from my research, it would appear that if I create a system partition that is within the 137.4 GB range of the motherboard BIOS, the BIOS will be able to see the system partition hardware-related files, i.e., boot.ini, ntldr, ntdetect and will be able to transfer the rest of the boot process to the boot partition, the partition where the \Windows files are installed, allowing the system to start up, properly, without seeing the dreated "disk read error occurred." From what I have been able to find out, this is all the BIOS needs and once it transfers the boot process over to the boot partition, it is up to Windows XP to finish the boot process, which, I believe, has nothing to do with the BIOS and should not be affected by the 28-bit LBA limitation. I am wondering if this is correct. Whether this is correct or not, will determine my partition scheme for my system rebuild.
I know that most people will not separate their system and boot partitions, but, this is the heart of my question. Since XP does allow the separation of the system and boot partition, can I simply create a small system partition (C:), perhaps only 50 MB or so, which will be well within the 137.4 GB range of the BIOS and use the rest of my 250 GB hard drive for my XP boot partition for the D:\Windows directories and data files, as if this drive were one big "C:" drive, as it was before. I want to keep things simple and have all of my files on one partition, if I can, without splitting the drive into two equal-sized partitions.
I hope I am making sense; I sincerely appreciate your help. Thank you, Ken and everyone else.
