Whether you're using Windows 7 on a PC or a laptop, you may think you need to make a choice between performance and battery life. However, thanks to a selection of what Microsoft calls Power Plans its possible to strike a balance between the two. These are simply a collection of hardware and system settings that manage how your PC uses power. These can either be used to maximise performance of your machine, or even improve the eco-friendliness of your device by reducing the amount of energy it uses. Rather than having to individually tweak each of the settings every time you want to increase battery life or boost performance, you can simply select a Power Plan and the hard work is done for you. Here's how to change a Power Plan in Windows 7.

Step one
From the Start menu open the Control Panel.

Step two
Choose Hardware and Sound and then select Choose a power plan from the Power Options section.

Step three
There are three plans available, Balanced, which is the recommended plan and offers full performance when you need it while reducing power when the machine is inactive. This is joined by Power Save that reduces system performance to ensure the best battery life possible. Meanwhile High Performance, which can be viewed by pressing Show additional plans, will maximise screen brightness and performance but at a cost of battery life. Simply select which of these power plans you'd like to use.

Step four
You can also manually adjust the power plan settings to suit you by simply clicking Change plan setting next to the Power Plan you want to edit. Now you'll be given the ability to adjust when the display is switched off and after how much time inactive the machine goes to sleep. Simply select the appropriate interval from the drop down menu displayed. If you're using Windows 7 on a laptop you'll be offered these setting for both when the device is plugged in and running off the battery.

Step five
Select Change advanced power settings to adjust individual aspects such as when multimedia is being played back, or what happens to USB ports. Press Apply followed by OK. Now you'll be returned to the Edit power plan window. When you're happy with your changes to the Power Plan, press Save Changes.