You will have to make due with the Basic version unless you backed up the installer you downloaded when purchasing it the first time.
BTW Limewire has made a lot of changes in the last 6 months, so try the free basic version and see how you like it. Then if happy with it consider buying it again. (And this time save your installer to external or disk)
Here is the link for the new BETA (Now with torrent support):
http://www.gnutellaforums.com/showthread.php?t=63125
BTW would maybe be smart to wait for the final version before buying again, because that wont be released until all bugs are taken care of.