Project backup save

So I have messed up some of my previous unity projects and I was thinking if there was a way to make another save of a unity project on a hard disk.
if I just copy paste the project folder into the hard disk, the textures, terrains and many other things disappear from the scene but are still found in the hierarchy.
If anyone knows please tell me.

Start using versioning systems. Your life will become easier. Unity versioning docs
You can also do all your work in Dropbox and let it take care of your files. Then you dont even need your server.

I never had problems with copying project folders. Just be sure to not only copy the assets folder, but all of it. And when you want to go back to an older state, don’t just copy&paste the old folder over the new one, either remove it first, or rename the folder.

Unity BackupProject: Unity Asset Store - The Best Assets for Game Making