A while ago I was troubled by a tool that was installed with the software for my Asus P5B-E motherboard: aaCenter did show up in the task switch window because it had just it’s desastrous "ASUS ACPI Cneter"[sic] main window hidden.
I recently updated the Asus software, including PC Probe II, now version V1.04.19, and, tada, aaCenter is no longer run by default.
But, (there’s always a "but"), it is started when PC Probe II is launched. And it doesn’t exit with PC Probe II. And PC Probe II is going awry when it’s not running.
A quick look with Process Explorer and Process Monitor as well as playing with the SpeedFan tool, it goes to show this little software engineering gem seems to read ACPI information about temperatures, fan speeds and voltages, put that in the registry (HKCUSoftwareASUSAASP) and update the mainboard management chip data (at least the power supply fan speed).
So removing it may harm you, if you’re monitoring your motherboard hardware or depend otherwise on ACPI information for temperature management.