Windows 7: w7x64: explorer context menu: entry for all file types?

Im using a 32bit mass file renaming tool called "rename-it!" (http://sourceforge.net/projects/renameit/), have had no problems using it on Windows 7 x86.
However, on x64 the explorer context menu is missing.

In a similar situation (with another program) under WinXP x86 I recall being able to edit entries per file extension in the registry, so I was wondering if there is a place in the Windows 7 x64 registry where I could "fix" the association with rename-it with some tinkering..?
The idea is that it should pop up in the context menu in explorer, no matter what file type (and how many files) are selected.

Any ideas?