Where can I find a free/good NLVE?

Hi!



My son has made a DIY "film". I want to edit it and combine music to it.



I don't know much about editing a home-made film digitally (non-linear editing system). I am a audio fanatic and I have a home studio. My DAW is PT 11.3.1 on PC Win 7.



Where can I find a simple digital picture editing program? I mean a free one or trial version?



Thanks for your help!



Regards,

Kari-Pekka

Where can I find a free/good NLVE?