Convert msi to xpi

What is the difference between .msi and .xpi?

Name: Microsoft Windows Installer Installation Package; Efficient XML Interchange Data

Description: It is a file that store all information needed by the Windows Installer to install or uninstall a software. It contains all the requirements for efficient and flawless package installation on Windows OS.; Efficient XML Interchange (EXI) is a binary XML format for exchange of data on a computer network. It was developed by the W3C's Efficient Extensible Interchange Working Group and is one of the most prominent efforts to encode XML documents in a binary data format, rather than plain text. Using EXI format reduces the verbosity of XML documents as well as the cost of parsing. Improvements in the performance of writing (generating) content depends on the speed of the medium being written to, the methods and quality of actual implementations.