What algorithm did Windows XP use to choose your initial user picture?
Summary
Raymond Chen explains that Windows XP selected the initial user picture using a one-pass reservoir sampling algorithm implemented by RtlRandomEx seeded with GetTickCount. The piece highlights benefits such as reduced file-system I/O and handling directory changes gracefully, and notes a safety stop after sampling 100 pictures. This provides insight into Windows internals and RNG design from an historical perspective.