Teach you how to create a folder that can't be deleted

Start---Run--cmd
Enter dos
Enter the disk where you want to create the file, for example, d-disk
Input
d:< Br> enter the d disk
then create a file, the format must be optimistic
input
md 123..\\
"123" on behalf of the file name, change yourself. Remember The last two points and slashes can't be less
so you create a folder of "123..", you can see if you can't open it, you can't delete it.
Since there are folders, It's ok, how do you use it?
Start---Run---cmd
start d:\\123..\\
Open it, then you can put it in this folder Something, and the view size is 0kb
Is it going to be?
The delete folder command is
rd 123..\\