Enable Privilges

function EnablePrivilege(const Privilege: string; fEnable: Boolean; out
  PreviousState: Boolean): DWORD;
var
  Token        : THandle;
  NewState     : TTokenPrivileges;
  Luid         : TLargeInteger;
  PrevState    : TTokenPrivileges;
  Return       : DWORD;
begin
  PreviousState := True;
  if (GetVersion() > $80000000) then
    // Win9x
    Result := ERROR_SUCCESS
  else
  begin
    // WinNT
    if not OpenProcessToken(GetCurrentProcess(), MAXIMUM_ALLOWED, Token) then
      Result := GetLastError()
    else
    try
      if not LookupPrivilegeValue(nil, PChar(Privilege), Luid) then
        Result := GetLastError()
      else
      begin
        NewState.PrivilegeCount := 1;
        NewState.Privileges[0].Luid := Luid;
        if fEnable then
          NewState.Privileges[0].Attributes := SE_PRIVILEGE_ENABLED
        else
          NewState.Privileges[0].Attributes := 0;
        if not AdjustTokenPrivileges(Token, False, NewState,
          SizeOf(TTokenPrivileges), PrevState, Return) then
          Result := GetLastError()
        else
        begin
          Result := ERROR_SUCCESS;
          PreviousState :=
            (PrevState.Privileges[0].Attributes and SE_PRIVILEGE_ENABLED <> 0);
        end;
      end;
    finally
      CloseHandle(Token);
    end;
  end;
end;