How To Drag HTML and MP4 without them opening up?

[arthur brogard]

I was trying to sort out a folder full of lots of mp4's and html's and pdf's. The pdf's were alright but the html's and the mp4's would open up when I clicked on them to try a 'bulk selection', you know? Sometimes I could get them to go one by one but many times they'd beat me and open up. It was/is all a hassle.
Is there some tweak I can do to stop this quickfire opening up?
Or perhaps some third party file manager might be the go?