Over the last year I've seen an increasing number of EP installations on AX 2012 R3 and I had to recall what permissions the user installing has to be granted.
The quick summary is as follows:
- be part of the System administrator role in Microsoft Dynamics AX;
- be part of the Administrators group in Windows on the Web server;
- be part of the Farm Administrators group in SharePoint;
- be part of the dbcreator role on the instance of SQL Server that is used for SharePoint;
- be part of the the WSS_Content_Application_Pools database role in the SharePoint_Config database.