How to open .ADDIN file extension?

If you cannot open a new file that has been saved in the .ADDIN format you need to download the appropriate software. The manufacturer of .ADDIN files is Microsoft; .ADDIN files belong to the Developer 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 .ADDIN files. Activities performed in the order described should solve the problems with all the files in the .ADDIN format.

• What is .ADDIN file?
• How to open .ADDIN file?
• What is .ADDIN file?