Solution

MS Excel is a spreadsheet application developed by Microsoft and is part of the Microsoft Office Suite. It is used for data analysis, calculations, charting, and data visualization, but it is not an operating system.

The other options are all Operating Systems (OS):

• Windows 10: An operating system developed by Microsoft.
• Linux: A popular open-source operating system used in various devices and servers.
• DOS (Disk Operating System): An older operating system used in early personal computers.

Therefore, MS Excel is not an operating system.