I have opened XPE to do some power analysis, but the top row of buttons are disabled.
Macros are enabled, and this process worked previously.
However I have recently done a Windows Update and since then the buttons are disabled with Excel 2010.
Please verify which Windows Update you received.
You can review Windows Updates by going to the Start Menu-> Windows Update -> View Update History.
Follow the steps below (Details at http://support.microsoft.com/kb/3025036/EN-US):
The pre-requisite for these patches is Microsoft Office 2010 Service Pack 2.
Follow the steps below (Details at http://www.adamfowlerit.com/2014/12/12/excel-macros-broken-with-windows-update/):
Microsoft describes .exd files in the following link.
The renaming or deleting of these files should not cause serious issues.