PART — I
Make your folders totally invisible …
1)Make a new folder
2)Now rename the folder with a space(U have to hold ALT key and type 0160).
3)Now u have a folder with out a name.
4)Right click on the folder>properties>customize. Click on change icon.
5)Scroll a bit, u should find some empty spaces, Click on any one of them.click ok

Thats it, it has become invisible .

PART — II
Follow these steps.
1.Suppose you have a folder named abcd in D:\abcd.
2.In the same drive next to the folder create a new notepad file with the exact statement
ren abcd abcd.{21EC2020-3AEA-1069-A2DD-08002B30309D}
3.Now save this text file as loc.bat
4.Create another notepad file and type
ren abcd.{21EC2020-3AEA-1069-A2DD-08002B30309D} abcd
5.Save this as key.bat
6.Now there are two batch files . Double click loc.bat and your folder will change into Control Panel and its contents cannot be viewed .
7.To open the folder double click key.bat and you get back your original folder .
8.For more safety keep the key.bat in another location .Only for unlocking copy paste to the original location and double click .

If you combine this with the hidden folder trick, it will be impossible for anyone else to access it