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Also check to see what else is running in the background. I heard Windows 8 has quite a few things running so that might be your problem. Open your Task Manager and take a look there.
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Harisheldon 
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basicj2525 10 pts. To see all answers submitted to the Answer Wiki: View Answer History.
Wireless networking consumes [lots of] energy.
Much more info is needed. Which Windows 8 was used? A preview release? A final? What are all of the processes that you have running? What are all of the battery-related settings? How “new” is the laptop? How new is the battery? What battery is it? How was it charged/discharged in the past? All of that (and possibly more) is added to various reports that Windows 8 can be worse at handling batteries than Windows 7 in at least some systems. — Tom
Recently I faced the same situation, when tried to install windows 8. It provides 3.5 to 4 hours of backup on Windows 7 while I got only 2 to 2.5 on windows 8. Tricks I’ve done which also u can try…..1. Run Windows Update2. I set brightness to minimum & make battery mode to power saver3. And of course install all latest device driversThe last i.e. no.3 is very important. After that I am getting solid battery life.
“Recently I faced the same situation, when tried to install windows 8. It provides 3.5 to 4 hours of backup on Windows 7 while I got only 2 to 2.5 on windows 8. Tricks I’ve done which also u can try…..1. Run Windows Update2. I set brightness to minimum & make battery mode to power saver3. And of course install all latest device driversThe last i.e. no.3 is very important. After that I am getting solid battery life. ”
Read the answer from its real author: http://superuser.com/questions/497473/poor-battery-life-windows-8
Well, the OP didn’t say he/she installed Windows 8, as far as I can see, it was only downloaded…