Installing XLC should be just a matter of running XLC_Ribbon_setup.exe which is downloaded from the ExcelCalcs website. If for any reason you cannot see the XLC tab on Excel’s Ribbon then here are a few checks you could make:
  1. Check that all the file XLC.xlam is available in the installation directory (the default is C:\Program Files\XLC). You can open XLC.xlam and you should be able to see the XLC tab in Excel.
  2. Check that add-in is selected via Excel>File>Options>Add-ins at the bottom of the page you’ll see ‘Manage’ press the ‘Go’ button and ensure that ‘XLC Addin for Excel’ is listed and the checkbox is ticked.
  3. You may also need to check your security settings Excel>File>Options>Trust Center at the bottom of the page you’ll find the ‘Trust Center Settings’ button. Make the XLC installation directory a trusted location (default is C:\Program Files (x86)\XLC).