Open MSI File

MSI format and extension files are used to install, remove and update software.

MSI installer packages its content similar to a compressed ZIP file, which allows it to be extracted with decompression software such as 7zip or WinZIP.

Therefore, MSI package file contains all the files that will be necessary to install and the information on the path in which they should be installed.

It is important to know that extracting the content is not enough to complete the installation, since when executing an MSI file, it is opened by a software called Windows Installer that, in addition to extracting the content, is in charge of performing all the installation actions. declared in it.

These actions, registered in an MSI file and executed by Windows Installer, and which are Standard Actions, range from placing each component in a specific path, writing or deleting files, writing or modifying registry entries, among others.

However, there are situations where the installer developers might need to take other actions beyond Standard Actions, and therefore MSI files are critically important.

For these cases, there are the so-called Custom Actions, which can be written with greater freedom and allow the use of executables, either using DLLs or Scripts.

As a last comment, although these features are mostly used to develop safe and legitimate software installers, they can also be used for malicious purposes.