Helping people with computers... one answer at a time.

System and registry cleaners often report wildly differing results. The reason? Sales tactics and no clear consensus of what it means to be clean.

I have a couple of good cleaning programs to protect my computer (which are usually recommended by you!). But occasionally, I get suckered into running a 'free trial' of a program (like a registry cleaner). I may have just run my cleaner and have been given a clean bill of health, but when I run the 'free trial', I invariably get hundreds of errors. Why?

It really, really, really depends on the utility that you're running.

But, ultimately, this type of behavior is what leads me and many others to not recommend entire classes of registry and system cleaning utilities.

It's not just a few bad apples that spoil the entire bunch; in this class of utility, it's often difficult to find an apple worth biting into at all.

The Sales Tactic

The most common reason why you'll see free trials reporting lots of errors is simple: they want to scare you into purchasing their product to clean up what they supposedly found.

“The biggest single piece of advice that I have here is to resist the temptation to try the latest and greatest system cleanup utility or registry cleaner's free trial.”

I say "supposedly" because the most disreputable scanners aren't above reporting "problems" that aren't even there. Thus, when you do purchase the program, they find that all's well presumably because of their exceptional technology; in reality, the utility did nothing.

That's not to say that there aren't utilities that actually do clean things up - there most certainly are. But many of those that I've seen are still not above overstating the risk of what they find and clean up. For example, some may claim that having 1,000 cookies is a serious performance and security risk. In my opinion, it's neither. Buy into their rhetoric and you'll be convinced that you need to purchase their product to clean it all up, which they then do.

Which brings up the second problem with these cleaners.

Differences of Opinion

Ask 100 tech pundits about this topic and you'll get 100 different opinions.

The same is true for the creators of system cleaning software. Even among legitimate programs, a wide variety of opinions exist about what is and is not something worthy of cleaning and what can be cleaned safely.

The net result is that you could run one program to completion, have it report that your machine is 100% clean, and then immediately run another that might report that it's riddled with cruft.

And there's no absolute measure of which of them is "right".

There just isn't a formal definition of what it means for a machine to be "dirty". Oh, there are common things that most would agree could be considered dirt, but once you stray out of that fairly safe, common area, things become unclear quickly.

And even on those items that everyone might consider technically "dirt", you'll also find a variety of opinions about whether there's any value in cleaning it up.

Resist the Temptation

The biggest single piece of advice that I have here is to resist the temptation to try the latest and greatest system cleanup utility or registry cleaner's free trial. At a minimum, only run tools that you've heard of and that have a good reputation from people you trust.

If you've never heard of it and the only words in support are from the tool's own site or advertisements, walk away.

The potential for harm or just wasting your money is too great.

My Recommendation

Besides using only trusted tools, my single biggest piece of advice is simply this: don't go trying to fix problems that you don't have.

Put another way, I ignore cleanup utilities entirely until I'm actually experiencing and fighting a problem. Only then will I consider using a utility - and even then, I'm still more likely to target the specific problem rather than use a more general purpose "fix everything" utility.

But that's just me.

As I said, there are many opinions on this. If you do elect to invest in a cleanup utility, I strongly suggest that you do the research first to find out if it's worth what you're about to pay for it.

While it's possible that it can be, often times, it simply isn't.

(Oh, and make sure to backup first before running any cleanup utility - just in case.)

Article C4971 - November 2, 2011 « »

Share this article with your friends:

Share this article on Facebook Tweet this article Email a link to this article
Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

Not what you needed?

November 2, 2011 7:13 PM

A recent article in PCWorld magazine took a look at cleanup utilities from another angle: PC speed improvement. In an article entitled, “Cleanup Utilities: Can They Speed Up Your PC” (August 2011 issue), the conclusion reached after testing was that “in most cases the cleanup utilities scarcely made a difference in overall system performance.” After running a utility, “your PC’s overall performance is unlikely to change much.” The magazine’s advice was to uninstall old programs and save your money for hardware upgrade instead. The magazine tested four popular cleanup utilities (Ashampoo WinOptimizer 7, Iolo System Mechanic 10, Piriform CCleaner, and 360Amigo System Speedup) on five well-used PCs of various specs and generations. The test results surprised even the magazine. Perhaps another reason, in addition to those stated by Leo, for PC users not to be so eager to use system cleanup utilities.

November 3, 2011 7:00 AM

if i use them it's only to clean cookies and system temp and browser cookies and temp internet files. i never use them to do a system clean or reg clean i don't touch that area at all.

William C. CURTIS
November 3, 2011 9:45 AM

Tks Leo. You've answered my question but one of the programs I'm talking about is advertised above.

Ken B
November 3, 2011 1:47 PM

Yes, "context-sensitive ads" can be a bit... "interesting". The ad I see is for one of those "speed up my PC" utilities.

What gets me are those TV ads with people claiming that the (supposedly-free) utility made their systems faster than when they first bought the system, along with claims that spam and popups can cause "permanent damage" to your computer. (I'm sure you know what I'm talking about, but I don't want to mention names here.) I did a little checking into several variants of the same utility under different names, and while every malware scanner gave the free utility a clean bill of health, all the free utility did was a registry scan. (It didn't even include a "registry cleaner" in the free program.) It did absolutely nothing about looking for malware or other issues. For that, you had to buy their rather expensive "remote support" service, and allow one of their "techs" to remotely access and "clean" your system. I understand that that service was something in the order of a few hundred dollars.

Mark J
November 3, 2011 3:40 PM

That's one of the ironies of context sensitive ads. Often an article warning about a certain product will cause an ad for that product to appear.

November 8, 2011 8:58 AM

This reminds me: One time my mom's computer was perfectly fine -- I know because I was using it for something just the day before. Anyways, she saw a banner ad for a registry cleaner and decided to install it.

Long story made short, it trashed the system. I was able to fix it so the computer would actually run, but still had to reinstall the OS because it didn't run properly.

Shortly afterwards, I installed Firefox + AdBlock Plus for her.

November 8, 2011 12:30 PM

I learned the hard way about using registry cleaners. What i use and like the best is CCleaner, i use it to clean cookies only i wont use it to clean my registry. Simple reason not to use a registry cleaner is, there is many shared dll files that if removed could make other programs not work. The only way i would recommend using a registry cleaner is if you know what you are doing and know what is safe to remove.

November 8, 2011 7:42 PM

If I had a "cleaner" program for sale, and were of a mind to try to bilk people out of their money,|I would include in the free download a standard video that looked very official and showed my software apparently finding lots of problems. After all, who really reads all that? And who knows enough to dig through the code to find it? (hint: usually not the people who would fall for such things) Then, of course, once my software was actually purchased, it would play another video of all those problems being fixed. The innocent and naive customer would be relieved that my software fixed all of the "problems," I would be richer, and in most cases no one would be the wiser that my software actually did nothing. People are easy to con because A) Everyone wants something for nothing, and B) No one wants to believe they have been conned, once they actually have. So they fool themselves. "Hey, look, this app/page/whatever NEVER used to open this fast!"

I am, by the way, pretty convinced that this is the way many of these free cleaners operate. If I can think of it, you may be sure many other people who are far less scrupulous than me have as well.

I am always very wary of the sites that offer "free" anything and have lots of banners and ads for other things that are obviously bogus. People I know say "Oh, yeah, the ads are bogus, but the actual product is legit!" Yeah, right.

November 8, 2011 9:09 PM

I have a few cleaners, what I do is run all of them one by one without removing errors.
The number of errors vary to such an extent it becomes unimaginable.In one cleaner it was just about a screen length 30-35 errors, in other it was mote than 500 or so errors.Just the cleaner I have is free it does not matter, I clean form all the 4 I have.
It is clear way of making a aggressive sale for their product that this many error comes. I have heard that some cleaners are virus oriented, they contain virus or infect the computer being cleaned by the virus.

Jim H
November 8, 2011 11:50 PM

I don't mind some utilities help in cleaning jobs like temp files and left-over internet clutter. But I did learn long ago that registry cleaners are risky business. They can cause certain programs to stop working correctly. It's on their tech help sites so i don't mind sharing, but every Roxio Media Creator I have ever used fro 6 to present was harmed by registry cleaners. With programs looking for 'security risks' I have had my TiVo Desktop software crashed so my PC was unable to communicate with the TiVo unit because it removed the server. These programs always alert about anything that can access the internet even if the is a perfectly legitimate reason for doing so. It can be quite tedious picking and selecting throught them and excluding them.

I also experimented before with trial versions of these utilities where i would run one and it showed no errors and then I could run another and get thousands of errors.

I think the ones that advertise on TV, especially the "Does your email take more than 3 seconds to download?" are exceptionally deceptive. That email statement alone has so many variables that have nothing to do with anything wrong with a computer or the presence of malware it is an alarm by itself.

November 9, 2011 4:10 AM

I use ccleaner along with advanced system care freeware and I am satisfied,
Thank you.

Jeff M
November 9, 2011 5:33 AM

I am a computer tech and I have seen more customers get convinced by either advertising or on the advice of "tech" experts around the web. Most are overkill at best and harmful at worst. One customer had installed ten of these on his system and it took around 30 minutes to get the PC to boot.

November 9, 2011 4:07 PM

With Ccleaner you can the check boxes of what you want cleaned and it works just fine for me.

November 12, 2011 7:23 AM


As the article outlines, I don't recommend any. I recommend only addressing problems your experiencing, and then with tools specifically for that problem.
November 12, 2011 8:47 AM

That would be this article:
Whats the best registry cleaner

Ed P.
December 9, 2011 8:39 PM

I ran the " free" registry cleaner scan that was offered on your own blog. I realize that you do not necessarily endorse your advertiser but in this case I figured that you would not allow an advertiser to cause harm. I was wrong. I did not fall for their offer but from then on I could not boot up my computer without first having to delete their ad to buy their registry cleaner. This went on for months and months until I was able to delete their software out of my computer. I will never open a "free" sample again. That site was Uniblue.

Mark J
December 10, 2011 1:54 AM

Most ads in Ask Leo are automatically place there directly by Google Ad-Sense and are not screened. Here's an article explaining how it works.

What's the difference between an ad and your recommendation?

December 13, 2011 10:04 AM

I use CCleaner because it works for remove of junk files, temps, and history. CCleaner is not over active as in other ultility cleaners. I use other tools in CCleaner but tell my end users to just use the top two items.

As for bad system cleaners, I have removed over 100 cases of this scam. The police have shut down most cases of this scam by stopping money flow. Scam artist are in jail now. Number of cases now have drop to null.

Comments on this entry are closed.

If you have a question, start by using the search box up at the top of the page - there's a very good chance that your question has already been answered on Ask Leo!.

If you don't find your answer, head out to to ask your question.