I discovered the other day that my Dell Latitude D400 (Intel 855GM chipset) was not being throttled back to 600Mhz when the load on the CPU was low. Instead it was pegged at 1700Mhz. Unfortunately it looks like Windows 7 doesn't support CPU scaling on the Centrino / Pentium M based systems. The only solution I've found for this so far (from another forum) is to use RMClock: RMClock Utility. Products. CPU Rightmark Works a treat. When set up using the "Performance on Demand" profile my CPU now throttles back to 600Mhz at rest, and scales up towards 1700Mhz when the system is under load. Hopefully my battery will last a bit longer now as well! Hope this helps someone else out as well.