WD20NPVX Reformat to 512

[PC_Cobbler]

As per this WDC article, XP will format an AF drive to 512, but note how doing so “will lead to extreme performance loss on the drive.”
http://wdc.custhelp.com/app/answers/detail/a_id/5341/~/how-to-use-the-acronis-alignment-tool-to-realign-an-advanced-format-drive