First, add a File Type Set to your project. It'll be named FileTypes1 initially, but better rename it to "DropTypes". Add file types to it that you like to accept. To accept any file, click on the center of these buttons in the IDE's File Type Set editor:

Choose special/any.
Next, add this line to the Open
event of the control or window that should allow drops:
me.AcceptFileDrop DropTypes.All
Then add this code to the control's or window's DropObject
event:
if obj.FolderItemAvailable then
dim f as FolderItem = obj.FolderItem
' Now you have the file reference in f.
' Get the path:
dim path as String = f.NativePath ' (in older RB versions, use *f.AbsolutePath* instead)
' Show the path:
MsgBox path
end