Board Thread:General Discussion/@comment-68.41.219.52-20130904015114/@comment-24382898-20140105082114

OMG. I had the same problem! Because Vocaloid registry codes are so clingy, you need to get rid of those codes. Here's a software that will do that for you:

here it is

I used it and my Vocaloids work like a charm! Just uninstall all your Vocaloid components with this software. Keep your download files, though, just uninstall the components.