I've never liked CCleaner, but at least a few years ago its registry cleaner didn't have issues with false positives. As I've said before, I think Wise Disk Cleaner is a much better option. It should find more junk to clean and lacks a registry cleaner, which is a plus.
Of course, cleaners are frowned upon by many, but I still daily use PortableApps.com version of CCleaner, with winapp2.ini via CCEnhancer. No registry clean. And regularly Wise Disk Cleaner (my first choice), Kerish Doctor. Never any issues.
CCleaner is safe to use if you don't use the registry cleaner. Wise Disk Cleaner and Kerish Doctor are also safe. While Kerish Doctor does include a registry cleaner, it won't delete valid registry keys, making it safe to use.
ccleaner is portable itself, you only need a "portable.dat" in same folder and thats available with any official build: https://www.ccleaner.com/ccleaner/builds to speak in general - NO cleaner is needed. at least wise ist one of the worst from my experience. the package itself is dubious from my view, like any cleaner which include registry, files, etc. it does not makes sense to clean up each day or each week, nor a month, maybe once a year. windows own cleanmgr.exe which is system-incorporated and where the feedback to programs is send. eg when i clean up cache from firefox with another cleaner firefox will throw me errors and wrong shown pages. its an external destruction of current files without any need. the vendors of such cleaners will make us believe hw neccessary their product are to keep windows clean and fast - and in special "fast" is fud.
When using the registry cleaner in CCleaner it will ask you if you want to backup changes to the registry. If problems develope you can always merge/add changes back into registry.
Yes, but it's always better to use a registry cleaner which won't delete valid registry keys. In which case the backup (which all registry cleaners create), won't be needed.
After a registry clean up, the "problem" may be that the next day comes and your computer won't even start. It happened to me! Thus, I couldn't fix the registry unless the computer got started, and I couldn't start the computer until the registry got fixed. Fortunately, I had made a full system image a few days before messing with the registry. Thus, I was able to restore an image to get my computer back in operation. Another possible glitch: a registry cleaning may screw up an app that is used only once in a while. Thus it may be days or weeks after the clean up that you try & run the app and it flops. Will you associate the flop with the days-ago registry cleaning? Maybe yes, maybe no. IMO, using a registry cleaning app is something like hiring a college freshman veterinary student to do open-heart surgery on your little daughter. By the way, I like your user name. Took me a moment to figure it out.
The average user will just blindly let a registry cleaner delete every so called error it finds, without checking first. If you use a safe registry cleaner, which doesn't ever delete valid registry keys, this won't be an issue.
Suggested re-wording: "If you use a safe(?) registry cleaner which hasn't (so far) ever deleted valid registry keys (as far as I know), this might not be an issue."
Yes, that is is better wording. But as an example, I've run Kerish Doctor on many computers and have only seen a single, very minor false positive. While in theory it could cause problems, in practice, I believe the chance of it ever causing issues is probably zero.
@roger m Just because an app like CCleaner includes a registry cleaner doesn't mean it should be used. If you do use it then proactive steps need to be taken to protect yourself. That's true of any cleaner tool being used. Disagree with backup not being needed on any registry cleaning app that is used. Registry cleaners are not perfect. All it takes is that one time to cause an issue.
@bellgamin Not advocating everyone should use a registry cleaner. Editing the Windows registry either manually or using a registry cleaner could create problems as you mentioned. Having image backup(s) to restore is good idea whether your using a registry cleaner or not. When installing software and/or security updates and uninstalling you should have reliable backups in the event your OS and/or apps don't function properly. Thanks for comment on user name.
FWIW: "Why Using a Registry Cleaner Won’t Speed Up Your PC or Fix Crashes We’ve said it again and again: Registry cleaners don’t speed up your PC. At best, they’re a waste of time — and often money. At worst, they can cause problems by removing registry entries they shouldn’t..." https://www.howtogeek.com/171633/why-using-a-registry-cleaner-wont-speed-up-your-pc-or-fix-crashes/
There's also the fact that Kerish Doctor can automatically add items to its ignore list in addition to its rollback feature. I feel this greatly reduces any potential issues that could occur.
Roger, I agree 1000%!!! Kerish Doctor is THE best computer cleaner/fixer I have ever used. Its diagnostic & fixer capabilities have saved me from those stupid errors I make from time to time. They update very often and respond to my emails within a few hours.
I just installed KD2020 and did a full scan. I unchecked everything except one thing and it told me the unchecked ones would not show up in the scan anymore unless i did something in some setting. I can't find that setting to add back everything i unchecked before.