All windows before 98SE had memory leaks every time a new thread was spawned. Memory leaks in newer versions of windows are due to sloppy user programs (mainly

All windows before 98SE had memory leaks every time a new thread was spawned. Memory leaks in newer versions of windows are due to sloppy user programs (mainly handles that aren't released properly but a precise programming can reduce those to zero) and rarely bad drivers but the core itself is stable.