4GB of RAM, Hiberfil.sys and Windows Vista
If you use Windows, you may of noticed a large hiberfil.sys folder in your system root (Say, C:\) this is the hibernation file that Windows uses to store the contents of ram when you hibernate your system.
Before Vista, if you wanted to free up some space, you could simply just turn off hibernation and delete the file.
Unfortunately Windows Vista likes to keep it around even with hibernation turned off in the Power Management settings. In my case a 4GB file. It’s undeleteable and who know’s why simply having hibernation off would still require you to keep the file.
To get rid of it run your command prompt (cmd.exe) as Administrator then type:
powercfg -h off