Speed up your Win8.1 on boot #2

Fast startup should be activated when you install Windows 8.1, but in the case it's turned OFF you can activated it on Control Panel.

Control Panel > Power Options > "Choose what the power bottons do" in the left panel and:

You can do this in Windows 8 too

With "Turn on fast startup" Windows uses the "Kernel Hibernation" to speed up boot times.

For more info:
http://blogs.msdn.com/b/b8/archive/2011/09/08/delivering-fast-boot-times-in-windows-8.aspx