Sandra Wall asked if she can trust CCleaner “to delete the correct problems in the registry.”

First of all, I love CCleaner. It can wipe free space on your hard drive so that your deleted files can never be recovered. It can tell you what kind of files are taking up room on your drive. It can manage and delete restore points, and clean various bits of Windows not associated with the registry. If I did feel the need to clean my Registry, I would probably pick CCleaner for the job.

But I see no reason to clean my Registry.

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Any flaw in your Registry that’s causing serious problems is going to be difficult and dangerous for a program to detect. “Fixing” it could easily make things worse. So, to avoid irate tech support calls, the developers of most Registry cleaners play it safe, looking for keys that no longer serve a purpose, such as those left over from uninstalled programs.

And keys that no longer serve a purpose don’t really hurt you.

Yes, they result in an unnecessarily large Registry. But the size of the Windows Registry is inconsequential with today’s hard drives and even SSDs. It doesn’t take up a lot of room.

In theory, a large Registry slows down the boot process. But it doesn’t slow it down by much. Before writing this article, I ran CCleaner’s Registry tool. It found 1,420 “issues.” After the cleanup, there were only 77. In other words, more than 95 percent of the junk in my Registry was removed. If that speeded up my PC’s boot time at all, it was so little I couldn’t see the difference.

Cleaning your Registry with CCleaner won’t hurt anything. But it won’t help, either.