Is there really any need for software like CCleaner? I really can't see how cleaning a few bits here and there and the registry and deleting temp files that will be back again in a few days help performance on modern systems at all.

I understand that they help you save space (temporarily), but if you have too little space left for disk optimization to work properly you should just get a new harddrive IMO. With SSD coming in fast, this is even less of an issue as they do random access really fast.

  • 7
    But when you have a 128GB SSD and realize that 20GB of temp files, Windows Update crap, old cache and other junk is eating up most of your SSD, it's nice to reclaim some of that space for other more important things like _ _ _ _. (fill in your important things. no more than four letters! hehe)
    – kobaltz
    Dec 27, 2011 at 23:27
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    But shouldn't you move your temp directory and everything that changes rapidly off from your ssd anyways to save those precious writing cycles? That's at least what I did - moved every monolythic software (e.g. Win7, Programming Tools etc.) that does not change often onto the SSD, moved everything that changes (Temp Directory, Desktop, Savegames etc.) onto a normal HDD Partition? I'd even move the registry there if it were possible.
    – Sorcy
    Dec 28, 2011 at 9:36

6 Answers 6


I have used CCleaner for years. I don't really think of it as a performance booster and I'm not sure that the developer thinks of it that way either.

The primary reason for using CCleaner is to remove the history of what you've been doing - starting with your browser cache, cookies, recently used file lists and many other logs and records. This is why it offers the option of overwriting the removed data up to 35 times! That's not about improving performance, it's about not leaving any traces. If privacy is a concern, it's a very valuable tool.

The registry cleaner is a secondary function but if you frequently install and remove software, it can surprise you with how many "dead" registry entries it will find and remove. I don't think this makes a big difference in performance, perhaps more of a benefit in reliability. It can fix problems that may arise when updating to new versions or with programs that connect to multiple file extensions, i.e. media players, etc.

In my opinion, it's worth using CCleaner occasionally (monthly?) if you aren't concerned with the privacy aspect - or very frequently if you are!


I wouldn't call it FUD, but the features that you describe are certainly becoming less and less necessary, in part due to what you already mentioned. However, CCleaner is a useful tool, if you know how to use it.

I regularly use it to fix installation issues where the installer will not work due to some leftover registry entries. Now I can go in manually to hunt them down, or do a sweep with CCleaner and let it do the grunt work--I have yet to see it fail to find what I'm looking for.

Of course, it also features a quick way of disabling startup items and from a (albeit on a low level) privacy aspect, the selective cookie cleaning is also nice. You can also download a community-built ini file that adds a lot more features to the cleaning tool, which is useful if you are a particularly obsessive cleaner.

Whether or not it aids performance, I don't know, as I haven't run any benchmarks. Perhaps placebo effect, but I do notice when I run it on client's systems who are not particularly IT savvy that the performance has increased substantially. On my own system, where I run it more regularly, I do not notice the slight performance boost it may warrant.

  • It still has a place, just a much smaller place.
    – surfasb
    Dec 27, 2011 at 23:48
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    Maybe this should be a separate question, but how do you learn what to clean and what to leave? I recently killed my old, dying XP by letting revo uninstaller remove everything it found for several apps I was removing. (I have a better XP in a vm, so it was no loss.)
    – Joe
    Jan 4, 2012 at 8:47
  • To be honest, trial and error, unless you know exactly what is going on behind the scenes for each option. Asking SU before clicking away will also be a good option as we have a large membership full of knowledge here. Finally, I can only say that I've never had an issue and I usually leave CCleaner on default settings. Your mileage may vary, of course, so your best bet is to ask first, click second.
    – Paul
    Jan 5, 2012 at 3:06

I mainly user CCleaner to free drive space when the drive is running low and just before I defrag the drive.

Doing a CCleaner just before a defrag mean the machine will not need to spend as much time moving "temporary" files around, plus the defrag program will have an easier time putting the non-temporary files in faster parts of the disk.

I know CCleaner helps with privacy (cookie deletion), but for performance, that is how I use CCleaner.


If you're talking about the registry cleaning function, there is not a single well-documented case of it ever "fixing" anything. Because the entries it removes are dead, they don't do anything. They have no measurable effect on performance. It is theoretically possible that they might confuse some program, and that removing them would fix that, but if that were true, the program would have to be broken. CCleaner is specifically designed not to change behavior, otherwise it would be much more likely to break things than fix them.

That said, I'm one of the "defrag my hard drive for thrills" type and broken registry entries bother me. So I remove them when I have nothing better to do.

CCleaner has other features as well, and some of the other answers here discuss them.

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    I "fixed" something just today with ccleaner. A client had a computer where a specific software just would not install. After running CCleaner, I found a leftover registry entry that was preventing the installer running again, as it thought the software was already installed. This is an issue I see quite often when software developers use NSIS as the install client. There's nothing wrong with NSIS, it's whoever creates the install package with it.
    – Paul
    Dec 28, 2011 at 1:20

Apart from cleaning all the cr*p from your PC, which is what the C in CCleaner originally stood for:

If you Launch the Application:

Click on Tools

The Uninstall Tab on the left hand side should be highlighted (if its not click on it).

This will display every Application that is installed on your PC.

Over on the lower right hand side you can then click on Save to text file...

This could prove very useful for references purposes.

CCleaner is actually multifunctional in its usage.

Going back to its original intended use however:

There is also a new way to clean & manage your PCs easily from anywhere, using CCleaner from the Cloud in the form an Application known as Agomo.


I package applications for automatic silent installation. Of course, some of my packages fail when building them, and some applications can't install (for various reasons) or install partially. CCleaner helps cleaning reg keys and fix my test environments. Another reason I use CCleaner is the startup manager, having everything there, in one page is easier to see what starts automatically and disable or delete them.

And, of course, another good reason to use CCleaner is for freeing up hard drive space. I also use CCEnhancer, which ads a bunch of extra applications to CCleaners list.

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