Check your processes
Everyone who has this problem I recommend downloading Process Explorer here: http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx
look out for constant low level CPU activity of 3 processes - dwm.exe (Desktop Window Manager), SearchProtocolHost.exe, SearchFilterHost.exe. Also keep an eye out for dllhost.exe when browsing folders in Windows Explorer- it seems there may be a bug in W7 that can cause the search and thumbnail to indexes to constantly delete and refresh themselves, which is obviously going to be bad for battery life......
Biting the hand that feeds IT
