Windows XP and Vista - Account Pictures

The default collection of pictures for user accounts can be found in the following folders:

in Vista - C:\ProgramData\Microsoft\User Account Pictures\Default Pictures\

in XP - C:\Documents and Settings\All Users\Application Data\Microsoft\User Account Pictures\Default Pictures\

The pictures are BMP, in Vista they are of 128x128 pixels and in XP - 48x48 pixels.