I don't know... why are you posting in the Forums instead of researching it?
Search our Knowledge Base where this is answered, or search the Forums as it has been answered many times. There is no "simple" answer. You must find out why your computer installation is not allowing you to do what thousands of other users have done... install using a Floppy or Memory Stick.
http://www.mtu.com/kb/index.php?action=kb&article=64
http://www.mtu.com/kb/index.php?action=kb&article=17
http://www.mtu.com/kb/index.php?action=kb&article=9
Yes, you have been wise and have Norton Ghost to fall back on while you research what might be wrong.