Hello kocko,
All third-party software are absolutely necessary to use WinReducer 8.1 v1.17 (hope you use this latest build), and this is why they are in reds !
Before starting using WinReducer, you need, at this screen (you screenshot), to click on each name to automatically download all necessary files : WinReducer will automatically extract all files and put them in the good folder !
For example : to install 7zip : click on the name "7zip", then click on the name "ImageX", and so on ... in fact, all checkboxes needs to be in green !
You could use this dedicated website page to inform you about the 1st installation procedure :
http://www.winreducer.net/wr81-installation.html
Best Regards.
winterstorm2050