OK so I have tested both the lightweight version I have used on a very old PC with a low powered Video card! And the second on a gaming PC as the Pro version does need some power to run it! These two are both great and safe to use. No Malware was found in either and they are Free! Whats not to like?! Both are free for personal use.
Best lightweight Video Editor for free! (Solved)
If you want a Free video editor and only have an old Windows machine maybe with a poor video card you could do a lot worse than download the FREE VideoPad from NCHsoftware.com Grab it its free and great for those older machines!
Look for the small print that says
Get it Free. A free video editor version is available for non-commercial use only. If you will be using it at home you can download the free version here.
Best Free professional Video Editor (SOLVED)
If you want a Free all singing and dancing professional Video Editor then grab DAVINCI RESOLVE! Its only expensive if you want the extra packages but runs perfectly well without them for most use say for YouTube.
Visit this page https://www.blackmagicdesign.com/uk/products/davinciresolve/
Then scroll down to the bottom of the page and select Free Version!