Those who frequently use both operating systems are advised to disable the Windows 8 Fast Startup feature. For this purpose, open the Control Panel and access the "Choose what the power button does" link under Power Options. Click on "Change settings that are currently unavailable"; this will reveal a panel with further options where you can uncheck "Turn on fast startup". Without the Fast Startup feature, Windows 8 will require slightly longer to start. The full Hibernate state that can be enabled on the same panel should be left unchecked, as Windows 8 appears to keep information on the state of all mounted filesystems in memory with this option as well.
With dual-boot systems, the problem can likely also be avoided by writing the GRUB 2 bootloader to a file instead of the first sector of the system disk; this file must then be integrated into the Windows 8 bootloader's boot configuration. Starting Linux via the Windows 8 bootloader mitigates the risk: with this variant, Windows will unmount its own partitions before booting a different system. The same approach is also used when dual booting Windows 7 and 8 to avoid problems with this configuration. To do this, the Windows 8 boot manager must be used; this will be the case if Windows 8 was installed after Windows 7.
The risk of data loss through Fast Startup or Hibernate doesn't only exist with parallel Linux/Windows installations, it also arises when a live version of Linux is booted – for example from a USB flash drive, CD or DVD. Users who only occasionally boot such Linux systems don't necessarily need to disable the Fast Startup option as they can simply boot Linux after having triggered a restart in Windows; this option still powers Windows down completely and allows other operating systems to be started safely.