The windows registry contains a lot of information. Its consistency can be checked with good commercial programs like Symantecâ„¢ System Works. But there are some small things I miss with those programs. Here is what SpyBot-S&D searches for:

• Missing help files – the registry contains information about the location of some help files. If this information points to incorrect directories, Spybot-S&D will inform you about and allow to fix.
  
  
• Missing shared DLLs – the registry contains a list of dynamic link libraries, where they are located and how many programs are using them. SpyBot-S&D checks if all locations are correct and allows to change them if not.
  
  
• Application paths – some applications (mostly those registered to a file extension) are registered in the registry. If they are pointing to a program file no longer existing, Spybot-S&D can change their path or delete their entry.
  
  
• Wrong Uninstall information – every program that has its own uninstall routine stores some information about it in the registry. If this information is incorrect, Spybot-S&D will tell you about. For example, the uninstall program may have been located inside a temp directory (there are lots of programs that stupid!).
  
  
• Broken Desktop Links – if one of the links on your desktop links to a file that no longer exists, Spybot-S&D will tell you and allow you to either point the link to another file or delete it.

Warning: Please be aware that changes to these items can corrupt your system! If you are not sure whether a setting is really a problem you´d better leave it alone!
This warning especially applies if you are using Microsoft Officeâ„¢. This software suite has some registry entries pointing to wrong directories and some even pointing to non-existent help files. I have changed the first, but I would not delete the other one, because they may well point to files that will be installed on that "Install on first use" basis.