How to open .XLSX file extension?

If you cannot open a new file that has been saved in the .XLSX format you need to download the appropriate software. The manufacturer of .XLSX files is Microsoft; .XLSX files belong to the Spreadsheet Files category. After downloading the application from the list available on our website just run an unknown file, and as the default set the newly installed application supporting the .XLSX files. Activities performed in the order described should solve the problems with all the files in the .XLSX format.