Yes, there is a redirection for 32-bit applications on 64-bit machines. See comments on your question, and also this SO answer.
If you target .Net 4 or above, you'll be able to access both Wow6432Node (used for 32-bit applications) and "standard" node (the one used for 64-bit applications) as RegistryKey.OpenBaseKey method provides a parameter of type RegistryView that allows choosing the correct node to use.
If you're using .Net 3.5 or previous version, then you'll have to use P/Invoke if you want to be able to read both 32/64 bit registry keys on a 64-bit machine. You'll have to use RegOpenKeyEx and specify KEY_WOW64_32KEY as flag for desired access. But this is another story and out of the scope of your question.
