System Software:
System software is a type of computer software that is designed to operate and control the computer hardware and provide a platform for running application software. It is essential for the functioning of a computer system and is responsible for managing various hardware components and providing a user interface for interaction.

Options:
a) Operating Software
b) Loader
c) Data driver
d) Firmware
e) Spreadsheet

Explanation:
Let's analyze each option to determine which one is not a system software.

a) Operating Software:
Operating software, also known as an operating system, is a type of system software that manages computer hardware and software resources and provides common services for computer programs. It is responsible for controlling the execution of computer programs and acts as an intermediary between the hardware and the user.

b) Loader:
A loader is a type of system software that is responsible for loading and executing programs on a computer. It is a part of the operating system and is used to load executable files into the computer's memory for execution. The loader performs various tasks such as allocating memory for the program, resolving external references, and setting up the execution environment.

c) Data driver:
Data driver is not a well-known term in the context of system software. It seems to be a typo or a misnomer. It is possible that the intended term is "device driver," which is a type of system software that allows the operating system to communicate with hardware devices. Device drivers provide an interface between the operating system and the hardware, enabling the operating system to control and utilize the hardware's functionality.

d) Firmware:
Firmware is a type of system software that is embedded in hardware devices. It provides low-level control over the hardware and is responsible for initializing and controlling the device. Firmware is typically stored in non-volatile memory and is essential for the proper functioning of the hardware.

e) Spreadsheet:
A spreadsheet is not a system software. It is an application software that is used for organizing, analyzing, and manipulating numerical data. Spreadsheets are commonly used for tasks such as budgeting, financial analysis, and data management. While spreadsheets can be used on a computer system, they are not a fundamental part of the system software.

Conclusion:
Based on the analysis, option e) Spreadsheet is not a system software. It is an application software used for organizing and analyzing data. The other options, a) Operating Software, b) Loader, c) Data driver (assuming it is device driver), and d) Firmware, are all types of system software that play essential roles in the functioning of a computer system.