Auto Power Plan Switch Manager for Windows 7
Branded computers such as Acer comes with their own power manager software called ePower Management which is meant to auto select the power plans based on the current state of power usage. If the laptop is connected to the power outlet, then normally it would auto set the power plan to a high performance plan and will automatically set to power saver if the battery level goes low. Balanced power plan will normally be selected when you have just plgged in the power.
If you have a custom built laptop that does not come with such software, Windows 7 power options in control panel offers you to select your preferred plans but you would have to manually do it. To automate the switching of power plans, you can use an intelligent software called Power Plan Assistant.
Once installed, it loads an icon in system tray where you can easily select to use Power Saver, Balanced or High Performance power plan. By default double clicking on the icon will turn off the display to save power. You can also set the program to auto lock your computer when powering off the display for instant security. It has nice dynamic notification area icon in taskbar and also skinning to make the interface looks nicer. The auto power management is disabled by default and you will have to set it up by right clicking on the icon, go to Power Plan Assistant Settings.
Power Plan Assistant is designed specifically for Windows 7 operating system both 32 and 64 bit. It is a donationware which means it can endlessly be used without charge but a donation to the author is appreciated.