I could manually create 4k aligned partition (with linux tools, eg. live cd), that would start at LBA sector 64 (not at sector 63 as default in Windows XP installer). I do not remember, but I guess that I've read somewhere that Windows XP won't boot unless the boot partition starts only at sector 63. So, is this true? Reference?

  • I have disassembled the boot sector from my XP that has been there since 2004, and it does have the assumed partition start sector hard-coded. – ivan_pozdeev Dec 13 '15 at 19:52

Answer: yes, Windows XP SP3 should boot if installed on partition that starts on sector other than 63. For Windows XP SP2, there's a hotfix from Microsoft: http://support.microsoft.com/kb/931760.

At first I was thinking that the only way for Windows XP to deal with advanced format drives is through the hardware jumper on the drive itself (which virtually shifts all sectors to the aligned position). But that's not true. There are software utilities such as WD Align (or similar from other drive manufacturers) which, I make assumption, do the following:

  • physically relocate disk partitions with all data to new aligned location,
  • update partition table in MBR to reflect that new location.

So in that case (after partition relocation), Windows XP now sits in a partition that doesn't start at sector 63 anymore. And it works.

  • That "WD Align" is based on Acronis Disk Director. Yes, it does that - and adjusts filesystem structures as well. It also only performs operations on WD Advanced Format drives. – ivan_pozdeev Dec 16 '15 at 3:53

There's a good article on advanced format drives on bit-tech. Windows XP does indeed start at sector 63, which cases problems for these drives. However, all this means is that if you don't take other steps, you'll pay a penalty when writing data. Many advanced format drives (for example, the western digital drives) have a jumper to deal with this, by adding an offset to the sector mapping. Western digital also offers the WD Align software, which moves misaligned partitions around. Anandtech covers this, and other aspects.

In summary, Advanced Format drives are a bit of a problem for operating systems as old as Windows XP, but there are some fairly straight-forward workarounds if you insist on using XP.

  • Doesn't answer the question, just a bunch of thoughts on the subject. – ivan_pozdeev Feb 18 '16 at 10:41

windows xp does not boot for me when installed on an aligned partition (i.e. one that does not start at 63). It will recognise the partition install from cd to the bit where it says copying files but when it reboots to finish install will give an error. similarly if i allow the xp cd to create the partition (starting at sector 63) it will install and work fine (but will not be aligned). Then when I used the tool to align partitions from the Western Digital site it would no longer boot. Waiting for a response from Western Digital but am not holding my breath. I used a Windows XP (SP2 I think) CD. SP3 may be different dunno.

  • 3
    You may need SP3. I use the Win 7 PE to partition and format discs, then install XP SP3 from an i386 folder on my Win 7 USB key. It works fine. – afrazier Apr 13 '11 at 23:55

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