ERUNT is a great free registry backup and recovery tool:
http://home.t-online.de/home/lars.hederer/erunt/
The best thing abou it is that the restore executable can be run from dos or console at a pinch: you don't have to have access to regedit.
But Scarecrow's right -- it won't help you transfer programs to a new installation. Moreover, when the registry's bloxxed, Erunt may get the registry back to a point where windows will boot fully, but it rarely leaves things in a state where all programs are operable. Usually, I find that a full reinstall of the OS is called for in that instance.