Make your folder invisble ( it can not be seen even in hidden files)

Make a Folder in C drive rename it as "abc" without quotes.
Now open Command Prompt from Start Menu.
Type "attrib +s +h C:\abc" without quotes and press enter.
This command will Make your folder invisble and it can not be seen even in hidden files

and folders

To make it visible again type "attrib -s -h C:\abc"

You can lock any other folder also by changing the location C:\abc to address of your folder