An administrator attempts to install the latest security patches for an older server. When the administrator runs the patch installer, the install fails. The administrator tries again, and the installer fails again. Which of the following is the MOST likely reason for this?（）
A. The administrator improperly configured the virtual memory settings on the server.
B. The administrator is using incorrect patch switches for the install.
C. The administrator is trying to install security patches for software that is not installed.
D. The administrator is trying to install patches that require hard drive encryption on the server.
参考答案：C
