[Samba] disabling PC

[Felipe_G0NZ4LEZ_S4NTI4G0();]

Hi, when I disable a computer in Active Directory with wink8, winServer2003 and ADUC shows the following message: "Disabling the computer account prevents users on that computer from logging on to this domain". So, after that, I continue logging on that computer with users from my domain. Despite of disabling the PC, I can logging on the PC in the domain. So, what's the real function of disabling a computer? 
My Regards.