That is pretty simple in WinRescue. Just make a backup. It will backup the registry by default. You might want to look at the settings of the backup to make sure it will put the backup on D (it should put it in a subdirectory of WinRescue). Then once you have reinstalled Windows, run WinRescue, go to the Crash Fixer tab, find the backup and restore the registry.
I see one problem and that is that when you install new programs, they sometimes put files and drivers in the Windows directory, so you really need to backup the Windows directory too. But if you are going to restore all of the files that were in Windows, why would you reformat?
I guess you could just back up the registry, format, reinstall Windows, and then restore the registry. Then see what works and what doesn't, and be ready to reinstall the programs that do not work.
If you have damaged Windows and so what to reinstall, you can just reinstall Windows without formatting and it should keep the old registry in tact.