Registry Guy

Testing The Best Registry Cleaners

Mark Anderson explores 10 tools: To determine the "Best Registry Cleaner"

Best Registry Cleaner

The registry is a database which stores settings and options for the Windows operating system (XP, Vista, 7 etc.). Any changes a user makes to the "Control Panel" settings, installed or uninstalled software and file associations are all stored in the Windows Registry.

Over time changes can build up and create a large amount of obsolete and unnecessary entries. These unneeded entries collect overtime creating a very large Registry, slowing down windows and overall system performance and stability.

Finding and removing these obsolete entries in the registry is no easy task. In fact, manual edits to the registry can be disastrous. These problems are what led to the software so widely used today, called Registry Cleaner Software.

I tested the top selling Registry Cleaners on the Market - See The Results

Microsoft has made some efforts to make cleaning the registry easier with the unofficial and unsupported release of it's free registry cleaner software Regclean. However, with several of the Windows Operating systems using various different registry systems the free registry cleaner was never really updated and was eventually abandoned. Today Regclean is available on various non-Microsoft websites.

Now third-party Windows Registry Cleaners are everywhere. These tools are indeed deeming themselves "very useful". Although Windows XP and 7 are much harder to crash than Windows Vista, cleaning the registry needs to be part of a regular PC maintenance routine. One point to remember: when upgrading to a new operating system or re-installing windows on the same machine, if you are using the settings from a previous version or earlier installation of windows, the registry settings are carried along with the new install. This can create a bloated registry right from the beginning. See this summarized in my Free Registry Cleaner "Tips Tricks and Myths" PDF Report.

Case in point...

Usability Evaluations: A few weeks ago, I received a phone call from a former co-worker. He recently uninstalled about 20 small and rarely used applications from the control panel that had been collecting over the past year or so. I asked him if he thought he should run some registry cleaner software after all of the apps were uninstalled. He is a relatively knowledgeable user who usually maintained his PC fairly well, only he has insisted for years "Registry Cleaners were unnecessary and a waste of time and money." I obviously felt differently.

It was time we put this debate to rest. This situation was perfect, not only can I prove the importance of registry cleaning to him, but his machine would be a perfect test subject. He agreed. I knew the more changes a user makes to his system the more registry entries a given system would have. The more registry entries on the system the slower it operates. So what really is the BEST REGISTRY CLEANER SOFTWARE? Is a registry cleaner really necessary? If so, which one works the best? Well-we decided to find out. See the results for yourself below. Also look for my recommended Windows Registry Cleaners.

Note: He recently un-installed software, but there is one thing to remember: registry errors are many times caused by the upgrading, installation or un-installation of hardware.

So this leads us to another question: what exactly is a "registry error"? What criterion constitutes an error? A brief summary of initial runs during our test demonstrates the point very well:

Registry Cleaner Product Number Of Errors Returned
Registry Mechanic39 Errors
Registry Fix Registry Cleaner134 Errors
RegSweep59 Errors
Error Nuker100 Errors
RegClean531 Errors
Registry Repair28 Errors
AMUST Registry Cleaner97 Errors
RegCure Registry Optimizer198 Errors
GlarySoft Registry Repair307 Errors
Registry Doctor234 Errors

**No that is not a typo Regclean did indeed return 531 registry errors.

There are probably several reasons for the wide range of registry errors returned in our test. On one hand, there are major registry errors that will greatly affect system stability and an operating systems speed. On the other hand, there are many entries to the registry that are relatively minor and have no major impact on the system. These minor registry entries over time can build up, but individually they pose no real danger. It is my belief that these minor registry entries are the cause of the wide range in returned registry errors. Counting more of these minor entries drives up the error count. The only problem is that our tests revealed that the removal of these minor entries had no noticeable effect on the speed and stability of the test system.

So, do we simply let the amount of errors a given registry cleaner returns dictate the quality of its performance and depth of its cleaning? In short NO.

Q:If we can't let the returned errors tell us what registry cleaner software to use what can we use to gauge these tools?

A:The only answer is system performance. What purpose does a high number of corrected errors serve if the performance is still sluggish?

Let The Testing Begin...

Our test computer was running Windows XP Professional fully updated running an antivirus and firewall utility, regularly defragged and previously running fairly well. He however, never did run a registry cleaner. We made an exact copy of the contents of his hard rive on a disk so that in-between tests we could restore his system to the exact condition every time.

We then ran the 10 registry cleaner software tools one at a time to determine the best. We ran each one three times, rebooting the system in-between each run. Before any cleaning, his system took 1 minute and 29 seconds to fully boot up. We noted the number of returned errors (found and fixed), length of the boot up, and stability of system for each registry cleaner. Doing the tests in this manner insured each cleaner faced the same system conditions. We ran 3 consecutive tests with the same cleaner to see if once we repaired all the errors found on the first run what would the second and third run show? Is there accuracy between runs? Do the errors diminish as we go? On run three are there still any errors to be fixed, and why didn't it fix those errors on the first run? My theory is that a good registry cleaner should return repeatable results. If the analytical process it is using is accurate shouldn't it return accurate results? We thought so.

Our choice of registry cleaner software is by no means definitive. We formulated this list from a brief survey of our colleagues and felt the diversity in both price and usability made for a pretty good pool of testing subjects. So let's see how they did:

Best Windows Registry CleanerBest Windows Registry Cleaner

RegCure Registry Optimizer


Errors Found: The only program we tested that returned a perfect 198 on ALL three passes. That type of consistency and level of cleaning is exactly what we were looking for during these tests.

System Performance: Unbelievable. Brought boot to under a minute! 57 seconds is a very quick boot. System performance was also noticeably faster.

Ease of Use: Very easy to use. Giving the user the ability to do the cleanings manually or automatically is a great feature for the novice and the expert. Fast and thorough during testing.

Opinion: Our Choice. Two Thumbs way Up. Consistent correct level cleaning on a simple, easy to use interface makes this a winner.

Best Registry Cleaner

Registry Mechanic


Errors Found: When we ran the free trial version it found and removed 39 errors. It informed us that the paid version could remove an additional 58 problems. On subsequent runs it found 19 errors every time. We were not sure if these errors were unfixable or recurred every time after a reboot, nonetheless it found them every time.

System Performance: The boot up went from 1 minute 29 seconds to 1 minute and 21 seconds. Slight improvement on the boot up. System was stable and seemed to work slightly faster. Applications ran quicker and we could have more programs running simultaneously than pre-clean.

Ease of Use: Very sleek and simple straight-forward interface. It ran quickly and was very stable in its operation.

Opinion: Easy to use the fact that it found 19 errors on every subsequent run did concern us. I'm not sure it was cleaning deep enough. I would NOT recommend this tool. Among the most popular, but I have to go Thumbs down here.

Best Windows Registry Cleaner

Registry Fix Registry Cleaner


Errors Found: Registry Fix found 134 items on the first pass, 110 in the second and 109 in the third.

System Performance: Boot time went to 1 minute 12 seconds. An increase of 19% that's good. System operated noticeably faster.

Ease of Use: Well designed product. Includes a nice feature called "Registry Defragmentation". This feature is used to optimize and enhance the system performance.

Opinion: Thumbs up. An overall great product. I would have liked to see more consistency on the errors returned each pass, but I feel the level of cleaning was sufficient on each test we ran.

Best Registry Cleaner



Errors Found: On the first run Regsweep found 59 errors. Not a problem until run two when it reported 123, then 109 errors on run three. Very inconsistent. A cause for concern.

System Performance: System actually took longer to boot from 1 min 29 secs to 1 min 38 secs. Our assumption here is several of the keys needed to be rebuilt upon startup.

Ease of Use: Very nice interface, displays the activity of the product well. Great explanation of what it has done and what it wants to do.

Opinion: Thumbs down. The wide range in returned errors makes this product tough to trust. Additionally slowing the boot up did not help.

Best Registry Cleaner

Error Nuker


Errors Found: First pass came back with 100 errors. Not bad until pass two came back with 80 and pass three returned 68. We could no get it to return the same number twice. Unclear as to why.

System Performance: Improved the boot by 8 seconds, however once up the systems performance was unchanged.

Ease of Use: Great clean user-interface. Relatively easy to use. They clearly spent lots of time and money on the look of this product.

Opinion: Another example of inconsistent registry cleaning. The winner returned the same exact number three times, this one clearly did not. Thumbs down.

Best Registry Cleaner



Errors Found: Initially it found 531 errors. The highest out of all that we tested. Pass two returned with 115 errors and pass three 122. Alarming that pass one would be so high, then the subsequent tests would be so low, but consistent with each other. We concluded the errors in pass one were being artificially inflated based on the second and third results.

System Performance: RegClean had no noticeable impact on system performance. Boot time remained exactly the same. System did not speed up in any way.

Ease of Use: This was the product's other downside. It was very difficult to install, we eventually concluded that the key code sent to us simply did not work. An upside was the program does use the Recursive CSCAN algorithm, a constant among the better products we tested.

Opinion: Good looking and very fast. The artificially high return of errors on the first run of the test is not a good sign. If a product is truly good these types of tricks are not necessary. A thumbs down.

Best Registry Cleaner

Registry Repair


Errors Found: First pass found 28 errors. Very low return compared to the others in the test. Pass two returned 32 and pass three was 41. We were a little concerned it was simply not cleaning deep enough compared to the rest of the programs.

System Performance: Improved boot up by 19 seconds. That is an increase of 11%-very good. System however actually worked slower. Applications took longer to launch most notably.

Ease of Use: Easy to use, installed easy and worked well. Very reasonable we thought.

Opinion: Thumbs down. First and foremost the program has to work. This one worked, but a little to too light.

Best Windows Registry Cleaner

GlarySoft Registry Repair


Errors Found: This program returned 307 errors on the first pass. 228 on the second pass and 291 on three. Fairly close, we were not too surprised by these results. The product tested well.

System Performance: Boot up was 1 minute, 23 seconds but the system was much faster and very stable-Noticeable improvements here.

Ease of Use: Not the slickest user interface of the programs we tested, but very efficient. It was easy to install and cleaned well, not too deep. Fixed most if not all of the errors that the other recommended products did.

Opinion: Thumbs up. Easy to use good depth, level cleaning.

Best Windows Registry Cleaner

AMUST Registry Cleaner


Errors Found: 97 errors on the first pass-not bad. Pass two returned 101 and pass three returned 112. Fairly close no real cause for concern here.

System Performance: Took an amazing 20 seconds off the boot up. System overall was much faster. Programs launched quicker operated better.

Ease of Use: Easy to use "Roll Back" feature is nice to undo any unwanted changes. Also detects and cleans the non-removable Embedded-null registry keys. Something many of the others did not do.

Opinion: Thumbs up. A very straight-forward product. Consistent and solid performance. Recommended.

Best Windows Registry Cleaner

Registry Doctor


Errors Found: Test one gave us 234 errors. A little higher than many of the others however in the same range. Pass two returned 201 and three came back with 212. Fairly close.

System Performance: Boot up time was 1 minute 20 seconds-Very good. System was slightly faster but not much.

Ease of Use: Very good functionality. Probably second in usability to RegCure. Fast and easy.

Opinion: The results of the test were good not great. However, the great interface and speed of this one make up for its slight inconsistency. Thumbs up.