Here is a way to hide your secret stuff in an image file.
1. First, select all the files you want to hide and create a compressed zip archive with those files by right-clicking after selecting them and choose 'Send to' and then 'Compressed (zipped) folder. Give the new archive a name of your choosing. I will go with the super secure Secrets.zip name.
2. Next we need an image. I downloaded this JPEG image of a minion to use.
3. Now I use the this copy command to hide my zip file to look like an ordinary image.
copy /b minion.jpg+Secrets.zip minionsecrets.jpg
You will get a confirmation that the file was created.
Now, go back to your folder and you will see another 'image file' that looks like and ordinary JPEG image and it even opens as an image.
4. How do I open it up to see the hidden files? In order to open this file you will need a program like 7-Zip installed. This is because Windows Explorer just sees the file as an image. First copy the path of the secret image by holding down the Shift key and right-clicking it. Then select 'Copy as path'.
Then open your 7-Zip program and paste the path you just copied for the file into the location bar of 7-Zip and hit enter.
And there you go, your files are shown and can be extracted.