Trailhead Support Center : Anonymous FTP
Our Anonymous FTP Site (upload only - new window will open - drag files onto white space)

If you have a large number of files or a few very large files that you need to get to us, you may be able to take advantage of our anonymous FTP services, which allows you to place files directly on our web server using internet explorer. (This only works on computers running Windows 2000 or Windows XP)

Open internet explorer
Go to tools>internet options>advanced Under "browsing" make sure that " Enable Folder view for FTP Sites" is checked.
Click OK
Quit Internet Explorer

Open Internet Explorer again and go to this address
ftp://trailheadweb.com/incoming/

You should be able to drag items from your desktop to the white area of Internet Explorer and you will get a notice that the files are being uploaded.

When you are done, quit Internet Explorer and send us an email telling us you placed some items there.

No one else will be able to see or access the items you placed there.
If you go back to the site ftp://trailheadweb.com/incoming/ the page
will appear empty.

Unfortunately this method won't work on all computers for all internet connections and since there are so many variables involved we are not able to trouble shoot individual machines.