CPU does not support long mode

I downloaded ubuntu 7.04d and it said to use on most computers option and i read on this some other guy who had a 32 bit processor and they told him to download this version so i did, but when i try to boot from cd it tells me this message exactly "Your CPU does not support long mode. Use a 32bit distribution." Can someone help with this? Where can i download a distro that will work with my cpu... thanx