You did not say what kind of mistake you made. You also did not say what version of Manager you were using or exactly what you are referring to as your “Manager folder.”
If you were able to recover all the files on your old drive, all you need to do is move your business data files to the application data folder on your new installation. See this Guide: Backup, restore, import, and transfer businesses | Manager.
@Patch is saying that you are looking at the wrong folder.
What you have restored from your backups is the folder that Manager was installed into.
But the folder that Manager stores application data (which is what you want) is located elsewhere.
You will need to go back to your old crashed computer and find the application data folder, which is different
Note that one of the links they posted says this:
In the desktop edition, your application data folder location is shown in the bottom left corner of the Businesses page.
It’s in the bottom-left of your ‘Businesses’ screen when you first open Manager. Check what the default is for Windows by opening Manager on your new computer, then check in that same location on your old crashed computer. It might be stored in the same place.