Anna,
If you are in reference to having to have Excel 2007 installed to use XLSX files even when you have a newer version installed. There are several workarounds depending upon which version of ArcGIS you are using. Please take a look at Understanding how to use Microsoft Excel files in ArcGIS and select your version of ArcMap for specific instructions.
You may need to install the Microsoft Access Database Engine 2010 Redistributable as Microsoft has discontinued support for the Office 2007 drivers. This package will install a set of components that can be used to facilitate transfer of data between 2010 Microsoft Office System files and non-Microsoft Office applications.
One other note, I believe you need to download and install the 32-bit version of the Microsoft Access Database Engine 2010 Redistributable even for 64-bit systems on ArcGIS Desktop and Pro.