Is Registry Defrag Useful?

I've been using ccleaner for many years now on Win xp, Vista and Win 7 and never had any problems. As far as registry goes, IMHO the whole system is broken from the beginning, entries for programs that I don't even remember I had installed and deleted still remain in the registry and maybe Windows itself knows how to take care of registry, but it's all those stupid little programs you install that do the writing into registry, no one knows why and what for. But as others already mentioned, cleaning registry is not safe and very few programs do it right and since as I said IMO the whole system is broken, it is very easy to mess something up and create a lot of problems. And here is my question: if every installed program writes to registry and always leaves "garbage" behind even after deletion, how long before registry is so big that it actually slows down the system? I always use portable applications that do not write to registry, unless I have no choice of course, I manually delete registry entries left behind after uninstall of a program and still my registry files are twice as big as when new.
If you do decide to use some sort of registry cleaner, make sure original registry is safely backed up and you know recovery procedures in case things go south and you can't even bootup (and I've seen that as well).
And BTW there is portable version of CCleaner, so it shouldn't be writing to registry and compound the problem you're trying to fix.

I've been using ccleaner for many years now on Win xp, Vista and Win 7 and never had any problems. As far as registry goes, IMHO the whole system is broken from the beginning, entries for programs that I don't even remember I had installed and deleted still remain in the registry and maybe Windows itself knows how to take care of registry, but it's all those stupid little programs you install that do the writing into registry, no one knows why and what for. But as others already mentioned, cleaning registry is not safe and very few programs do it right and since as I said IMO the whole system is broken, it is very easy to mess something up and create a lot of problems. And here is my question: if every installed program writes to registry and always leaves "garbage" behind even after deletion, how long before registry is so big that it actually slows down the system? I always use portable applications that do not write to registry, unless I have no choice of course, I manually delete registry entries left behind after uninstall of a program and still my registry files are twice as big as when new.
If you do decide to use some sort of registry cleaner, make sure original registry is safely backed up and you know recovery procedures in case things go south and you can't even bootup (and I've seen that as well).

According to Fred Langa, in an article written long ago in the XP heyday, "jv16 PowerTools" provides the best Registry Cleaner. However this thread is about Registry Defrag and not about Registry cleaning.

One can defrag Registry as often as one likes because it doesn't change the information stored in the Registry. However it doesn't speed up the computer perceptibly either. In practice therefore Registry defrag is hardly of any use.

So "cleaning" and "defragging" the registry are different. I've never even looked in to it but I assume in order to defrag the registry a 3rd party program must be used. I don't think CCleaner's cleaning counts.

And since Windows does not defrag the registry automatically as it does for the drives with Disk Defragmenter I don't see a need.

From my personal experience, or tragedies, depending on your point of view; I will never clean or compact the registry... Again!!

Nine months ago I purchased an new computer making the jump from XP to 7. Being a creature of habit I had the idea that I needed to clean, compact, edit, etc. the registry to keep Windows 7 running smooth as I did with XP. I was so wrong.

On the other hand the experience brought me to this forum which has taught me, among many other things, the importance of backups, images and to leave the registry alone unless closely supervised by those that know about such things.

Perhaps I will one day feel comfortable poking around in the registry as I do with XP but I need to learn a lot more before that happens.

Reasons registry cleaning is useful to me:
1. It scans some old software entries that may have any conflict once I installed a newer version.
2. Windows' Add/Remove programs is not smart enough to truly detect if a software is already uninstalled as it relies on the software's registry entries.
3. When a software installation is broken by another software (example: a startup entry that is messed up by a startup manager); reinstalling the software doesn't always fix it, so the registries that contain instructions must be removed first before making a successful installation.


Reason registry defragging is useful to me:
1. I have many softwares open at the same time. So defragging registry from time to time gives it a little boost without having to rely on RAM (especially if the software in question is something that I activate/deactivate/edit regularly). I don't expect speed difference though, but I always experience reduced amount of lagging.

I clean and defrag registry for purposes related to installed softwares. Some people may have different purposes so it always rely on the user how much useful these methods are.
I just find it funny that some people views registry cleaning+defragging as a drastic operation and has the potential to either break Windows (the OS itself) or give it a fifth wheel, and yet they end up in trouble because of one stupid mistake of not backing up their registry.
Anyway, my computer is more about the software I use than the OS running in it. And I' not a purist, so I guess I'm a little braver to try things.

In my opinion defragging the Registry doesn't do any harm whatsoever but Registry cleaning, particularly if done in the aggressive mode, can sometimes cause problem.