I want to remove the hiberfil.sys file in windows 7

After following the recommended instructions on removing the hiberfil.sys file or simply turning it off/on ala
c:\powercfg.exe -h off I recieve this message.
You do not have permmision to enable or disable the hibernate feature.

I have also made sure that I am admin on my computer and there is only one other account that is a guest account.

Can anyone help with this?
Thanks in advance