Master security override?

Hey guys, I try all different experiments on my computer. However vista seems to like to tell me access denied every once and a while.

My current project it to encrypt the SAM using the SYSTEM account to attempt to prevent password cracking via booting from disk.

Does anyone know if there is a way to either bypass, override or temporarily disable vistas security? It keeps giving me access denied, even running the command as nt authority\SYSTEM gets the denied message too.

Any ideas? Please don't say don't do it, I am doing it as soon as I find out how to get past this damm protocol. Assuming I find a way to circumvent it

Thanks