Hi Lisa
I was trying to go from 5.3 to 5.4. I just looked over a thread from about eight days ago which dealt with my same failure (at least symptomatically). In that thread Danish Innis sent an alternative setup link to Christian. I tried it to no avail. Here's what that failed with trouble is under c:\Program Files (x86) there is no InstallJammerRegistry directory....
(edited) Ah I see you mentioned hidden. I'll see if I can find the little devil. be back to you shortly.
Got the little devil. Here you go.(Please visit the site to view this file)
Erich