Corrupted profiles frequently prevent Outlook from progressing past the loading screen. Creating a new profile establishes a clean environment for Outlook to start. I have found that when this happens its due to the Account in windows needing to be updated. If you close outlook(make sure its not in the system tray) then click on start and type Domain, then find Access work or school. You should see the Microsoft account, click on it and disconnect it.

If you have a large number of items in any single folder, you may experience performance issues during certain operations. For more information, see Outlook performance issues when there are too many items or folders in a cached mode .ost or .pst file. When you install Office, an Inbox Repair Tool (SCANSPST.EXE) is also installed on your PC. The Inbox Repair Tool can resolve issues by scanning your Outlook data files and repairing errors. If your antivirus software includes integration with Outlook, you may experience performance issues.

You don’t have permission visit Fix Outlook Site to create an entry in this folder. Right-click the folder, and then click Properties to check your permissions for the folder. See the folder owner or your administrator to change your permissions.

These applications and services can interfere with Outlook. A Selective Startup or “clean boot” process can help you identify problems that are caused by application conflicts. Corrupted PST or OST data files can prevent Outlook from loading. Microsoft’s ScanPST tool can repair minor corruption