Hello Tim,
I've attached a sample, created with version 11.6.3 of AI, which uses backup and restore custom actions as it is described in the attached HTML article from our previous replies.
Just download and test it and let us know if this works. The sample was tested on a Windows 8.1 x64 machine. Please keep in mind that the "MyKey" registry should be created under "HKLM\Software\Wow6432Node" registry location on 64-bit machines.
All the best,
Daniel