Well, yeah - once you first open the applications, then they are installed, hence the “Click-to-Run.” Microsoft Office is never free, although it can be very reasonably priced if you have a student discount.

As other people have said, you have a few choices:

• If you really want to use an installed version of Microsoft Office, pay for the Office 365 subscription.
• If you really want to use an installed application, but don’t want to pay money, there’s LibreOffice, OpenOffice, and many others noted elsewhere.
• If you don’t need a locally installed application, you can use Word, Excel, and PowerPoint in Office Online, free for personal use; or the online Google suite of productivity applications.