The title says it all. Here are a few quotes from an article at the Malwarebytes blog:
"you shouldn't touch the registry with an infinitely long pole"
"You should not have to optimize, defragment, organize, streamline, clean, compress, fold, knit, wash, or color code your registry. Ever. Period. Nada. Zilch."
"Microsoft does not support the use of registry cleaners"
"Issues caused by these utilities may not be repairable and lost data may not be recoverable."
I think that you get the idea. I encourage you to read the article, if for no other reason than to learn a little bit about the registry and what it is used for. I also encourage you to purchase a subscription to Malwarebytes if you haven't done so already. It works in conjunction with your antivirus program to protect your computer.
Feel free to send me any questions or comments that you may have.