Delete a file "Open in another program"

Hello,

I'm trying to delete a file, but the following message keeps appearing: “This action cannot be completed because the folder or one of the files is open in another program”

After some research on forums, I found that one could try to delete it using the CMD command. I tried that, but it still doesn't work... It says it cannot find my folder, see image.



I also checked in “Properties” and the read-only option is enabled, I tried to remove it, but it automatically resets.

Lastly, every time I click on the bar to scroll up or down on a web page, a page from the AnyMP4 site (the file I’m trying to delete) pops up, it looks like a virus, but I had it scanned by my antivirus and it says everything is fine...

Thank you very much for your help!

P.S. I'm not very good with computers, so I need clear and precise step-by-step explanations. Thank you!