This step-by-step article explains how to share a Microsoft Excel workbook with other users. If you want several users to work in the same Excel workbook simultaneously, you can save the workbook as a shared workbook. Users can then enter data, insert rows and columns, add and change formulas, and change formatting.
If you're in an application that gives you a link that you can click on, the spinning circle usually means that Windows is busy; it's doing something... it might very well be loading IE9. It's not until IE9 has finished loading that it becomes visible and takes over the screen.
Now that Windows 10 is being distributed to users around the world, we know that there will be quite a few questions arising from new users. One that has already hit our inbox during the beta period is what's the little circle that occasionally shows up in the system tray?. The icon, which you can see at the top of this post, is Windows letting you know that an application is using your location. For example, if you open the Maps app, you will see the icon appear for a short time as the application orients to your location.