What is the BEST Registry Cleaner for Win 7 Ultimate or Pro 64 Bit version OS ?

Give me a shout: www.mousegolf.com

It's not about the size of the registry.  It's not about the speed of the PC.  Performance can mean different things.

The issue is this:

Orphaned Registry Entries can cause issues when you reinstall or upgrade an application.

I'm having issues with Visual Studio 2015 right now.  There are over 1,000 registry entries left after uninstallation and reinstalling it leaves the IDE unusable.  It just gives tons of errors about not being able to find files (that it is likely being told the location of in those registry entries), among other things.  The only way to get it to work is to "Repair" the installation, except that's completely broken because if you only install Visual Studio and Visual C++ w/MFC it will then enable ASP.NET on your machine.  It will install all manner of Windows SDKs (Windows 10 SDK and Tools, SQL Server Database Tools, etc.).

If you develop on a machine with a 128GB SSD (which is otherwise fine, since you used the custom install option), suddenly you see this product using over 1/3rd of your usable hard drive space - in some cases, you go from having 10GB of free space to something like...  Well, you don't have enough space to "repair" the installation because of the extra **** the installer is trying to install.

The only way to fix this, is to use a deep registry cleaner to completely remove the Visual Studio 14 Registry Entries after uninstalling it (Manually, because Microsoft can't be convinced to write a decent uninstaller).

This is a platform issue.  When someone uninstalls an application, the application should be completely uninstalled.  Orphaned Entries in the Registry do cause issues.  I've also seem PCs that would lock up immediately whenever LibreOffice was launched because of orphaned registry entries.  Then there are issues with Driver Settings after Uninstall/Reinstall or Upgrades, among other things.

There are so many issues that are registry-oriented.  The "Repair" option for most installations is used likely due to issues caused in the registry more than actual issues with files in the Program Files directory, these days.

The registry system is a hot mess.  They should have replaced it with something different a long time ago, IMO.

There's a big difference between managing Files/Settings/App Installations on OS X than on Windows, for example.  Complete night and day.

I have literally never had an application break simply because I uninstalled it and reinstalled it at a later date on OS X.  This happens all the time on Windows (2000, XP, Vista, 7, 8.x, and 10... It's been a perpetual issue ever since the applications moved full bore into throwing things into the registry instead of  using their own INI files, which one could easily hunt down and delete - disregarding issues with library registrations, etc.).

A lot of the information in this thread are being repeated by people who really don't have much experience dealing with issues derived from those situations.  They are merely repeating what they have read, and what Microsoft wants them to believe because the Registry is a hot mess and they are too lazy to move to a superior (and/or simpler) model; and seem incapable of really developing their own suitable utility to fix it.  They just tell you to System Restore and hope the issues are going to go away.

I haven't heard of anyone who's had to reinstall OS X because of plist issues.  I've had to reimage more than enough Windows PCs because of Registry issues making them run like ****.  Not performance wise, but in terms of blocking/breaking program installations/functionality, random error messages at boot and shutdown, etc.

Hallelujah, finally some one with some sense. I couldn't agree more with you.

It is a basic rule if you're working with computers. Remove all junk and clutter from sources, script files, configuration files, and also from the registry. If you keep all these files tidy and well organised, then it will be far more easy to look for problems. That is the first thing I always do when I'm confronted with problems, tidy up all files involved, and quite often by doing so the problem becomes apparent. Tidiness is absolutely necessary  if you work with computers.

So indeed, Microsoft should supply us with tools to check and clean the registry!!

It's not about the size of the registry.  It's not about the speed of the PC.  Performance can mean different things.

The issue is this:

Orphaned Registry Entries can cause issues when you reinstall or upgrade an application.

I don't think anyone will deny that there can be problems with the registry.  The problem is that people who have no business messing with the registry think that in general,  "errors" in the registry affect speed and performance.  In general, they do not, and the so-called "average user" who thinks he's doing routine maintenance by "cleaning" the registry is more likely to do harm by using a registry cleaner.   In many cases, an experienced user can use regedit to fix specific problems, so even then a registry cleaner is unnecessary.   Even in cases such as the one you describe, it's not possible to positively identify all of the registry entries that are related to a specific problem.  People who are completely ignorant of the workings of the registry should not, under any circumstances, attempt to "clean" it.

But average users, like me, also want a tool to sort out registry errors.  We're not experienced enough to understand regedit.  I am still using the non-updated version of Norton 360s registry cleaner - it has worked like a charm for the last 7 years and I am loathe to give it up.  It is not in the New Norton Security - I had to roll back to keep it, but I expect it is on borrowed time.  It seems to be very conservative in what it removes and rarely removes anything - unless I have installed or uninstalled a program.

I now have two laptops with this registry cleaner and one without.  The one without is not doing fine without it!  I dread installing or uninstalling anything.