Generally I would recommend using third party programs to clean up registry, built inWindows tools are enough. Especially with CCleaner, since among it’s other problems it even once was used to distribute malware with installer. It used to be legendary piece of software back in the day. But if you absolutely must use something, Glary Utilities is way more comprehensive and fully free, no premium or pro features being locked out. But even for that, I wouldn’t use it to clean registry. Though it has some other useful utilities.
Also in modern day, defragmenting registry is useless, since you should have Windows on SSD and SSDs font benefit from defragmentation, since all locations on the can be accessed with same fast speed, unlike mechanical drives where head had to travel all around to find those fragments, which severely slows it down. And if you still have hard drive, get SSD, like even on older computers, regular SATA SSD s are compatible and will make even dated system way more responsive. And smaller SSDs are now cheap. And I am not saying you should throw that old mechanical spinner out, you can use it as second drive, if possible and it will even feel bit more responsive when it isn’t constantly being accessed by OS, since that created quite a bit of chatter to OS drive.
Plus registry mostly won’t slow system down, it is few MB of data and modern hardware can handle it with ease. However bad entries can cause errors. But mostly, if you don’t mess with it, I had seen basically no issues with registry since like Windows 7 and no really need to mess with it unless you want to set something specific or fix some value, which registry cleaners and defraggers won’t do anyway. They will only Wie jets they seem unnecessary, making kilobytes if change in extreme scenarios and defrag it, which won’t help in SSD.
