Just a trick someone told me about to fix blackcipher lag.

I get 'Access is Denied" when I attempt this with Maplestory or BlackCipher. Most other progrms allow it except the antivirus, and some system stuff.

Have you tried pressing 'View processes of all users' (or something similar, the button with the administrator shield next to it) and then changing the cores used? I recall you had to do that if you wanted to change the priority of Maple, which was needed after Big Bang in EMS.