After disappointed with the internet connection speed I decided to do some "extra activities" with this wireless connection.
First I used Softperfect network Scanner for scanning the network and this is the result.

Hmm... There are several computer detected with this "simple" software. And what surprising me is I'm able to access their shared folder!!!
Then I tried to create a folder and then I realize that I already done "a simple hacking" with a "very simple" way...Not only one computer that I found have a writable shared folder, this is the another screenshot.
This time I add one folder and write a message for her/him.
I hope with little experience, you all will be aware of this and carefully using your shared folder...