Use SpeedStep to Minimize Fan Noise even while laptop is plugged in – via Win XP command line

If you want to throttle your CPU via SpeedStep even while plugged in, you need to change a power scheme. You can add a new from the Power Options dialog (“control powercfg.cpl”) and change the SpeedStep behaviour while on AC via “POWERCFG.EXE /CHANGE MyPowerConfig1LowCPUSpeed /processor-throttle-ac CONSTANT”. This will slower the CPU so the fan won’t go on.