should I worry about compatibility with some of my apps? What are the huge changes between Windows 7 and 10? it depends on the apps your are using, any documentation that I found addressed that issue very little. So without a complete list of the programs you have installed its impossible to tell if there would be any compatibility issues. However there are programs that allow you install apps in bulk like https://sourceforge.net/projects/sih/ so all you would have to do before the windows reinstall is take a pic of list of programs installed, which can be found in control panel.