I would suggest that the Windows Registry is best left to Windows itself to play with.
- Parts of it are inaccessible to regular users.
- Parts of it are inaccessible to certain types of application (32-bit processes running on 64-bit versions of Windows).
- It's a completely proprietary storage mechanism, which can change, without warning, with any upgrade or security patch.
- It's not easy to backup or restore parts of the Registry; it's really all or nothing.
- Values held therein aren't portable; they're fixed onto one particular machine.
Contrast that with a simple, text file held in the user's Roaming profile directory:
They are accessible to the user (with no security or U.A.C. complications), the format and content of that file are completely under your control, they get captured by a regular, file system backup, they can get carried, seamlessly, onto every machine that the user logs onto and they're less likely to get lost if you have to reinstall your operating system.