diff --git a/backend/README.md b/backend/README.md
index 5eec1ba..3688a35 100644
--- a/backend/README.md
+++ b/backend/README.md
@@ -12,6 +12,12 @@ sudo apt-get install net-tools
 sudo apt install ffmpeg
 ```
 
+- for windows, install 7-zip first:
+ https://www.7-zip.org/
+- then you can extract the ffmpeg-git-essentials.7z windows file her:
+
+https://www.gyan.dev/ffmpeg/builds/
+
 - install postgres
 ```
 sudo apt install libpq-dev