I don't know about Samba and stuff, and I don't care to share files on the network either. I just want to copy/move an ISO file form Ubuntu (the CD drive is not working) to a Windows 7 computer where I can safely burn it.
Even though you don't know Samba, it may be the easiest solution in this situation (or USB stick).
Just install samba, you'll also get GUI configuration tool:
sudo apt-get install samba
Go to menu System -> Administration -> Samba
Click green plus, add share. Select the directory containing your ISO. Select visible, on the 2nd tab grant access to everyone. You can share with everyone if you are in the private network, you will cancel this share later.
After this, you should see Ubuntu machine from Windows and be able to access that directory. I hope this helps.
General help with samba: https://help.ubuntu.com/community/Samba