You may follow the following steps to upload files through WinSCP FTP client :-
1) Download WinSCP from "http://winscp.net/eng/download.php" and run the
setup file.
2) StartWinSCP client from your desktop or another location where it is installed.
3) Enter the Username,Password andhostname (Your domain name) of your FTP
server provided by grabweb.
4) The SCP client will open a directory window located on the server on your desktop.
5) You can drag files to and from this window, other Explorer windows, and your desktop.