what is hiberfil.sys and how to remove
Windows has two power management modes that you can choose from: one is Sleep Mode, which keeps the PC running in a low power state so you can almost instantly get back to what you were working on. The other is Hibernate mode, which completely writes the memory out to the hard drive, and then powers the PC down entirely, so you can even take the battery out, put it back in, start back up, and be right back where you were.
Hibernate mode uses the hiberfil.sys file to store the the current state (memory) of the PC, and since it’s managed by Windows, you can’t delete the file.
Disable Hibernate (and Delete hiberfil.sys) in Windows 7 or Vista
You’ll need to open an administrator mode command prompt by right-clicking on the command prompt in the start menu, and then choosing Run as Administrator. Once you’re there, type in the following command:
powercfg -h off
Disabling Hibernate Mode in Windows XP
It’s a lot easier in Windows XP to get rid of Hibernate mode… in fact, we’ve already covered it before, but we’ll cover it again. Just head into Control Panel –> Power Options, and then find the Hibernate tab.