How to verify if you have Microsoft Office installed in a Default Location

Press Windows+E (the Windows button is between left Ctrl and left Alt).
File Explorer will open (the Windows 10 version is pictured, the appearance of yours may be different).
Navigate to the C:\Program Files and search for EXCEL.EXE in each (## = some number 14 or above). Note the location of the file.

You may have more than one of those folders if Microsoft Office has been upgraded several times or if multiple versions are installed but at least one of those folders will have EXCEL.EXE in it if Microsoft Office is installed in the default location.