How to clear the Vista system hibernation file

I use the Windows Vista system, when the C drive is divided into 10GB, after a few months of use, the system always prompts the C drive space is insufficient, I found out that there are C drive The file named hiberfil.sys has a volume of 2.5GB and cannot be deleted. After the hard disk is hung to other systems and deleted, it will automatically appear after restarting the system. Is this a virus?
This is the sleep file of the Vista system. This file will be generated when you need to use the sleep mode. If you don't want to use the hibernation function, you can disable the hibernation function by running the following command: If you type: powercfg -h off at the command prompt, you can turn off hibernation and delete the hiberfil.sys file.