Windows XP Hard Drive Size Limit


  • What's the scoop on hard drive size limits?

    I have heard there is a 2TB limit.

    Does that apply only to the system drive?

    I am running XP Home SP3 32 bit and using a 3TB external USB drive for backups and storage only, no system.

    It is recognized in Disk Managment as 3TB and MBR type. Also recognized in Windows Explorer.

    I can write to, read from and access files on this drive.

    So where is this 2TB limit?


    Thursday, August 11, 2011 2:54 PM


All replies

  • Hi,

    You heard correct in relation to the 2TB limit.

    On the external hard drive that you have which is 3TB, Is that a single partition formatted at 3TB or is it more than one partition?

    The root of this is Windows XP x86 is MBR only meaning that the limitation is to do with MBR

    Disks exceeding 2TB must use GPT which extends the limit significantly, however Windows XP does not have this support currently.

    A 32 bit version of windows generally will only see the protective MBR on a GPT disk.

    Information on Windows Disk support can be found here:

    Or course, that being said, I have seen external drive manufacturers combining a GPT loader in with their drives which will allow Windows XP x86 I/O on a drive greater than 2TB, this may be the case in your situation. The GPT loader I have come across is called Paragon GPT loader. I would imagine this would cause lag on I/O as it is another stack process.

    If you wish to share the make/model of the disk drive, I can further research it for you.

    Kind Regards,



    If you find my information useful, please rate it. :-)
    • Proposed as answer by MEIRLModerator Thursday, August 11, 2011 4:37 PM
    Thursday, August 11, 2011 4:37 PM
  • Hello, Martin,

    The drive in question is a Western Digital My Book Essential. It is connected via USB.

    Windows Disk Management shows it as a single partition of 3TB and an MBR boot type.

    As mentioned originally, I am accessing it apparently normally.

    I don't know another method of checking partitions. I tried Windows "diskpart.exe" but have trouble getting that to provide what I want. I'd like to "see" if it has more than one partition.

    I am aware of a Western Digial Answer ID 2754 that speaks of the 2TB limit.

    However, I'm not clear as to whether this limit only applies to drives which must be bootable and maybe does not apply to drives used as storage only, as mine is.

    Is the Master Boot Record (MBR) even used on storage only drives?

    Thanks for any suggestions, opinions or whatever.



    Thursday, August 11, 2011 7:48 PM
  • Hello, Vegan,

    Every site I visit tells me that I cannot use a drive in XP over 2TB.

    Well, my XP is apparently aware of my 3TB USB drive.

    I can write to it and read from it.

    Can anyone explain that?

    No one has yet.

    Saturday, August 13, 2011 6:02 PM
  • I believe you've got it.

    Here is a Western Digital forum post that explains it (I think).



    Saturday, August 13, 2011 6:25 PM
  • Hi Dick,

    Apologies for the delay responding.

    It appears that the WD Smartware application provides a 3rd party solution to Windows XP x86 to perform I/O @ 3TB as per

    As for how this works, im afriad you would need to address that with the good folks at WD


    Kind Regards,



    If you find my information useful, please rate it. :-)
    Wednesday, August 17, 2011 12:20 AM
  • I have windows xp pro 32 bit and installed 3 hard drives already 

    250 GB IDE

    320 GB SATA

    1 TB WD SATA

    Now i want to ask, is my condition applies to 2TB limit.  I want to put a 2 TB drive for only storage. Can anyone tell that if windows xp support it or not.

    Monday, October 21, 2013 9:27 AM
  • The MBR has 4 bytes to address sectors on a hard drive.  That allows 256^4 -1 = 4,294,967,295 (4G) sectors.  At 512 bytes per sector, that is 2TB.  At 1024 bytes per sector, that is 4TB.
    Wednesday, January 15, 2014 3:56 PM