Most of my short to medium size writing projects are done through Google Doc. I like this web tool because it is simple to use and does not have all that complex and intimidating clutter of authoring tools Word has. Anything you write on a Doc is automatically saved and synced to your Drive account across different devices.
This is the software I use for what I call heavy writing tasks like writing ebooks or chapters for my thesis. Scrivener is not free it costs $45 and there is a discount of 15% for educators and students. There is also a free trial period of 30 days to try it out before you buy it. Scrivener provides access to all the features of a full rich text editor: add tables, bullet points and images and format your text however you want. Here is a list of the features Scrivener provides to its users. If you are a graduate student or a struggling writer, Scrivener is a MUST have. Here is a great read about Scrivener: Thesis Writing with Scrivener.
If you still have that longing to Microsoft Word, try using OpenOffice. This is a free office suite competing with Microsoft Office. It includes word processor, spreadsheet, database, presentations. Compatible with MS Office files.