Windows 7 and Registry Cleaner Program
Windows 7 is the newest operating system by Microsoft and like the old versions of Windows, the registry in Windows requires cleaning. Not everyone recommends using a registry cleaner program unless you really need to, such as when you want to check if the systems' registry is full of junk, invalid entries, obsolete items or errors. No one can tell if a registry requires cleaning unless a trusted registry cleaning program or service has checked and provided a report on the status of the registry in Windows.
The registry structure of Windows 7 has no difference over Windows XP's registry simply because both are using a Windows NT-based operating system. Microsoft continues to use the same registry structure and the only difference is the user profile settings where you'll find Local Settings\Application Data\ in XP while Vista and Windows 7 has its user profile in AppData\Local.
Looking back at old article by Windows Expert and Microsoft employee, Mark Russinovich said:
"Registry junk is a Windows fact of life and that Registry cleaners will continue to have a place in the anal-sysadmin’s tool chest, at least until we’re all running .NET applications that store their per-user settings in XML files – and then of course we’ll need XML cleaners."
Like him, I recommend not using a registry cleaner but the fact is that sometimes the Windows registry can contain stuff that is no longer necessary. Another thing is that the Windows software was not made using the same settings and developmental tools.
Note that a registry cleaner program or service is not created to boost the performance of a computer but rather a tool to clean some unnecessary or remnants of already removed software. It's not necessary to use a registry cleaner in Windows and it's recommended only if you know what you're doing. The registry is the heart of Windows and the computer can become unstable if the program you use in cleaning the registry is buggy or not from trusted sources.
On the plus side, registry cleaners can help remove obsolete registry entries added by malware if your antivirus software has removed a malware but failed to remove traces of the malware in the registry.