does anyone know an Open Source Software for creating own MSI packages?
I wanna create an MSI file for installing a 3rd party Software. Currently it's installed via different commands (bat-file) and with different configuration files.
Is there a free Open Source software for recording an installation so that i get a MSI package as a result?
WiX is open source and is one of the best way to create MSI file. Some other tools (mostly commercial). Please check this answer for more information: WiX Quick Start Suggestions and links (has grown too much, maybe focus on first sections - including "Hello World & Hello WiX").
The linked answer contains links to descriptions of how WiX compares to other deployment software - both commercial and free as well as download links and "get started" recommendations.
I would recommend packaging with WiX, but if you want to capture the install as an MSI file you can check the discussion here: Capturing all changes during an application install on Windows.
You might want to try ISWix - a simple GUI front end for Wix that allows you to quickly throw together an installer by inspecting the config files and recreating the actions in Wix.
Finally you could download a trial version of Installshield AdminStudio - capture your install as an MSI using the built in capture tool. Then you can decompile the MSI with the tool dark.exe from Wix and recompile it as a Wix MSI to get around any trial restrictions in the Installshield capture.
You could even use the method suggested here: Tracking file and registry changes. As this answer mentions you could try to locate the old version of WININSTALL LE on a Windows 2000 Server CD in \VALUEADD\3RDPARTY\MGMT\WINSTLE.
Advanced Installer Architect allows capture, but I am not sure you can export a proper MSI file with the trial version.