
You need WiFi connection and an application called SwiFTP to be installed on your Android device. You can download this application from here (this might not be available on Google Play).

Once you have installed SwiFTP on your android mobile, launch this application and you will land on setup page. If you see homepage, click on setup button. On setup page, entire desired username and password. Now click on SAVE and you will be navigated to next page.

You will see a screen like above picture, from that screen get the WiFi URL which will look something like this ftp://192.168.2.100:2121. You are done with settings with mobile, now its time to work on computer.
- If you are using Windows XP, Go to My Computer > Tools > Map Network Drive
- If you are using Windows 7, Go to My Computer > Map Network Drive
A new window will pop up and you will see a couple options on the page. You need to click on "signup for online storage or connect to a network server"

After clicking that option, you will see a new window. Select the first option (Choose another network location) and click on NEXT.

The next page will ask you for "Internet or Network Address". Here you need to type your WiFi URL accurately that you get from SwiFTP app you installed in your android device.

Click on NEXT, in next box, make sure that you select "Log on anonymously” option. You will need to click on NEXT again and type whatever name you want to like when it asks you to enter a name for this network. Now click on Next and finally on Finish.
Now, you will see another drive in My Computer. Whenever you will open that drive you will be able to access all the data inside your android device. Simply copy paste files in your from your computer to SDcard folder of your Android device. Make sure you open SwiFTP and click on START before transferring files from PC to Android over WiFi.