I don't keep a folder of installed .sis files on my PC any more, but I do keep all the emails with reg codes and download links. If you do it this way, you can always be sure of having the latest version of things. Now I find that Handango / LCG want an additional $3 for me to re-download LCG Jukebox. I don't know if this is Handango or LCG policy, but I'm not paying it and will avoid both of them wherever possible in future.
Handango / LCG are beyond the pale now
If you have the codes, this should help:
http://mosh.nokia.com/content/40646C2D8D92CE14E040050A44302332