Every PC user probably knows that feeling of absolute delight when you’ve just bought a new computer and start using it: everything works so smoothly and properly, and it seems you can finally leave all the troubles of your annoying snail-like old machine in the past. The same is perhaps when you have a fresh and clean install of your OS. But time passes, you install and then uninstall various third-party software (let’s be honest, sometimes even from questionable sources), and things somehow appear to be not as rosy as you hoped. Minor or even major issues start emerging with more and more irritating frequency until the boiling point when you put your foot down and decide it’s high time you did something to finally stop that torture. You turn to the old friend Internet and, eventually, come up with an incredible solution: it turns out there are so many tools that promise to fix your problems with just a click of a button, sometimes even for free. That sounds great indeed, but are you really sure you can rely on them?
As a rule, this type of programs is called system optimization software. They can also go by such names as registry cleaners, system/disk repair software or something similar. Though they can be referred to in different ways, the idea behind those tools is practically the same: they search for temporary files and junk files, including ones from the registry, and destroy them in order to optimize your disk drive and make it operate more efficiently, thus, much faster. Seems reasonable, doesn’t it?
But the problem is that it is not temporary files that constantly slow down your PC, and neither do registry entries. The registry itself is actually a huge database of settings – both for the OS and for the software you install. For instance, if you install a program, it is very likely to save its settings to the registry. The operating system also saves pointers to that program. If the program is registered as the default program for a certain file type, your OS saves a registry entry in order to remember that it is the default program. When you uninstall this program, it may leave all its registry entries behind, which will stay there until you reinstall your operating system or clean them with some registry cleaner, that will scan the registry for outdated entries and remove them.
In reality, registry entries don’t influence your computer’s performance. They are actually fairly tiny, like a drop in the bucket, and removing even a couple of thousands won’t make any difference. Reducing the size of the registry would only make sense if our computers still had a tiny amount of memory or a very slow hard disk as they used to in the 1990s, but nowadays, with our modern speedy PCs, that will just go unnoticed. In fact, your computer can start operating more slowly when its file system gets fragmented, but you can easily fix this by running an inbuilt defragmentation utility that reorganizes the data on the storage medium. Another possible reason is that some malware has managed to slip into the system and your PC got infected. In this case, you obviously need to scan it by some trusted antivirus program and get rid of the malicious thug.
However, along with being unable to speed up your PC, some system repair tools can also cause great damage. Using such a program you can change the registry improperly or accidentally remove entries that were essential for some installed program, or, what would be close to a disaster, for your operating system. This can lead to software malfunctions and, in some cases, make your OS stop working entirely or render your data inaccessible. If you failed to prevent such a situation by creating a backup, you should immediately use some quality data recovery software, otherwise, you may lose your data for good and all.
So, as running such a utility is likely to cause more problems than it fixes, it comes at no surprise that Microsoft, who once created a registry cleaner of their own, advise people against using system optimization software and although they haven’t defined it as malicious software, they have characterized it as “unwanted,” which basically means saying these apps are completely unnecessary (https://support.microsoft.com/en-us/help/2563254/microsoft-support-policy-for-the-use-of-registry-cleaning-utilities). Furthermore, they decline any responsibility for the issues that may be induced by such utilities.
Of course, choosing to use them or not is entirely up to you, but considering the potential damage they can cause, one should truly think twice.