yes, it's possible to do it directly in internet explorer.
you should have a username, a pasword and the name of the ftp server (something like ftp.yourdomain.co.uk)
if you type into your internet explorer address bar...
ftp://username:
[email protected]
it should do the trick. once it's connected, the toolbar will change so that it looks more like the toolbar you get in windows explorer, so you'll have a 'folders' button. if you click that you should see the hierarchy of drives and folders down the left hand side. the ftp connection should appear in that hierarchy so you can simply drag and drop files onto the server.