I downloaded and installed AsteriskNOW Version 1.4.0 Beta 1.  As explained, the software and the website is still in beta.  The first sign of beta I saw was that there were no MD5SUM or  SHA1SUM values for the download.  I calculated the sums from my download as such:

md5sum asterisk-1.4.0-x86-disc1.iso && sha1sum asterisk-1.4.0-x86-disc1.iso
291853c2be640a2f1462c37cfac18507  asterisk-1.4.0-x86-disc1.iso
e29ccbd1ed7cecd40150953d38ab0ede96eaa396  asterisk-1.4.0-x86-disc1.iso

Once you have successfully downloaded the ISO file, you must create a disk from it.  Using Fedora Core 6 Linux, you can simply right click and select Write to disc.  If you are using Windows, it may be a little more difficult.  You will need to burn a disk from the ISO.  Note that this is not the same as simply writing the file to disk.  If you do not have the proper software, I recommend the excellent and free CD Burner Pro XP.  Thanks to the Ultimate Boot CD for Windows http://www.ubcd4win.com/index.htm for pointing me to this tool.

Once you have burned the disk you can use it to boot your machine.  I recommend choosing the option to remove all partitions.  Note that this will repartition and format your hard drive, removing all data.  You have been warned.  Another problem I ran into was with the admin password.