EXE files can be anything. Almost everything you run on your computer is started by an EXE file (exceptions are Windows itself, drivers). They contain executable code for a computer to run, and can do anything.
MSI files are database files, used by Windows Installer. They contain information about an application which is devided into features and components, and every component may hold files, registry data, shortcuts etc. The MSI file also contains the UI that is to be used for installing, and various other data such as any prerequisites to look for, custom actions to execute, the order of the installation procedure, whether to support Administrative installations, etc. It can also contain the actual files to be installed themselves (this isn't always the case though, the files can also be in an external CAB file or just as plain uncompressed files in a location where MSI can find them).
MSI files are the current recommended way of doing installations on Windows. The alternative is writing a program that performs the installation itself.
MSI files are executed by an EXE file that is part of Windows, called MSIEXEC.EXE. This application reads the data in the MSI file and executes the installation.
Windows Installer is pretty new, especially the newest version (3.0). Often installations that use MSI still come with an EXE (e.g. SETUP.EXE). This EXE is a so-called 'bootstrapper'. It doesn't perform the installation, it simply checks if the correct version of Windows Installer is present on the system, if not it launched the MSI Redistributable (MsiInstA.exe or MsiInstW.exe depending on the platform) and then launches MSIEXEC.EXE on the MSI file. In certain cases (especially Internet downloads), the MSI file and MSI redistributable are packed inside that EXE file, so you don't see they're there.
So installations can come in three flavours:
MSI files can only be installations. EXE files can be literally anything that can run on your computer.
A response file is a text file which contains one or more MIDL compiler command-line options. Installation Manager uses response files to complete installation operations silently.
For more information about response file, you can read these articles
EXE Application,When should we need to create a Response file (.iss file) what is the response file.How to create response file.
What is the help of response file.
I am not sure, but have you tried the suggestions given in the following article: http://www.eightforums.com/software-apps/16926-7-zip-problem.html
Thanik you for your very easy to understand explanation.
I have a question that may or may not be appropriate here. Sorry if it is.
I have Windows 8-1 and I'm tr;yng to get 7zip to function. I've tried so many many different things including uninstall and reinstall, restarting my computer, yadda ya. Thanks to you, I've just installed the .msi - 64 bit version. It still doesn't work.
Any ideas you'd be willing to share? Thanks very very much!