I will quickly explain a way to share your media through this router in a few steps and how to access its through windows 7 ftp.
1 Make a new user with password in your router settings so go to http://192.168.1.254/ log in and then in the top left click Administrator which will then show a few options in the user management page you will want to select add new user with admin privileges of user create a username and Password.
2 Plug in you flash drive or storage device to the back of the router.
3 Back to the router settings go to toolbox and then select content sharing and the go to configure at the top right.
4 This page you can tick the options you would like enabling Network File Server (Windows Networking), UPnP AV Media Server and FTP Server I have all of these enabled I left the name and description as default but change these if you wish.
5 In the list of connected disks you should select the partition and then apply these settings.
6 That should be it you should see your ftp server address if you go back into the overview connect with your newly created username and password you have created in step 1
7 The best way to put files on your flash or router drive ftp with windows 7 you can go to my computer at at the top click map network drive.
8 When this comes up you should see at the bottom an option in blue connect to a website that you can use to store your documents and pictures click next then choose a custom network location put in the address of your ftp which you will see in step 6 in the content sharing overview click next.
9 Untick logon anomalously and put in your username click next and name you connection if you wish.
This should be all you should now be able to share files over your network and outside on the web any problems or questions I can help just ask in the comments section.