I don't seem to have a Progeny PDF Printer entry in my registry editor, assuming that's where I should be looking. I have three places to look at software entries, in HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE and HKEY_CURRENT_CONFIG.
Progeny PDF Printer does not show up in any of the software directories within those directories.
In HKEY_CURRENT_USER -> Software, I see a directory called "Amyumi PDF Convertor" and in that directory a "Configurations" directory, but there is just one key in there, called (Default) with no set value.
In HKEY_LOCAL_MACHINE -> Software, I see a load of directories for various things, none of which are anything to do with this piece of software.
In HKEY_CURRENT_CONFIG -> Software, I see one directory called "CurrentControlSet", but there is again only one key, again called (Default) with no value.
I haven't rebooted yet (since installing), so I'll do that in case anything changes.