You install a managed add-in for Microsoft Excel like PowerPivot for Excel on a computer that is joined to a domain. However, Excel experiences a slow startup when the computer experiences high network latency.
Note This problem occurs in Microsoft Excel 2013, Microsoft Excel 2010, and Microsoft Office Excel 2007.
To resolve this problem, apply the hotfix that is described in the following Microsoft Knowledge Base (KB) article:
981574 The splash screen stays open longer than usual when you try to start Excel on a computer that has the .NET Framework 3.5 S981574 installed
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.