Currently, the registry path and registry key is hard-coded to Software\\GnuPG with key Install Directory in libkleo. For VSD/GPD this needs to be customizable.
for 64 bit VSD: Software\\GnuPG:VSD Install Directory
for 64 bit: Software\\GnuPG:Install Directory
for other (i.e. 32bit): Software\\Gpg4win:Install Directory