Registry Cleaner Tests - Why NOT To Use One!

Hello all, this post is aimed at those users who are contemplating using a registry cleaner. It's also aimed at the beginner to intermediate user, whom I think are the most likely to use one of the popular reg cleaners. I consider myself an intermediate user, and by no means, an advanced user.

I have a system image of a clean install of W7 x64 Home Premium, with all 'Windows Only' updates installed, including SP1, and all drivers are installed directly from my Dell disc. I have installed no software whatsoever. I used this image for both tests, by mounting it twice.

I wanted to see the results from running two very popular reg cleaners, CCleaner & Auslogics. So I mounted my system image, updated the 3 'Windows Only' updates that were missing, let the machine idle for 60min, rebooted, ran the W7 disc cleanup as admin (remove SP1 backup files) then ran the W7 defrag tool, and finally rebooted. I then installed avast! Free, Malwarebytes and Google Chrome. (I did this exact same procedure for both CCleaner and Auslogics tests) and I also installed CCleaner for test 1, and Auslogics for test 2. After all the software was installed and updated, I then used the machine as normal and checked the functionality of all the software. Once I was satisfied with normal behavior, I deleted the 4 installers via the Recycle Bin.

Test 1 (CCleaner): I opened up CCleaner and went straight to the reg cleaner (I never ran CCleaner's disc cleaner so it would be the same as the Auslogics test). CCleaner found 57 reg keys that were obsolete, so I removed them all and rebooted. I then used my machine for the rest of the day to see if anything was different. Well it was. avast! would no longer open the help file, and my wireless icon in the taskbar had a yellow ! for about 20 seconds on restart. Also, avast! now took over 5 seconds to open after clicking the tray icon. Malwarebytes functioned normally. Chrome now had an error message when I checked for updates via Chrome's "About Chrome" tab, and failed to update itself. I didn't notice any other problems, but I bet if I used my machine for a few weeks, some others would certainly pop up.

Test 2 (Auslogics): I opened up Auslogics and it found 149 registry problems, which I removed them all and rebooted. I used my machine for the rest of the day and tested everything the best I could to replicate test 1's usage test. I was able to open avast!'s help file, and avast! opened quickly, however, it no longer had any audio (avast! likes to talk to you). Chrome was a mess. On top of the error when trying to check for updates, web pages now took 7,8,10 seconds to open, and even after finally opening, the icon would spin again. But the big thing was, I no longer could see any images in Google search's image section.........Just blank sections with a blue icon in the corner. Again, MBAM was OK. The biggest problem, was boot time. Now my boot time was much, much longer, no matter how many times I rebooted. Like with CCleaner, I am 100% positive that more problems would pop up after weeks of use.

I tried to be as thorough as possible when replicating both tests and I feel very confident that I was. This post is aimed at those users who are just about ready to download one of these types of programs, to fix a problem, that doesn't exist. I hope this prevents an average user from making a mistake that they can not recover from.


Comments and criticism are both welcomed!

Both of those programs are very good programs used by people with the proper knowledge. I do agree with you that it can do damage to the registry. Using the fix all is where the problem is.Using the save button would probably help most. Any tool in the wrong hands can do damage.
Thank you for the test, job well done!

The real question is, how does a registry cleaner know a registry key or value is no longer needed? I've never seen a cleaner that didn't do damage when left to it's own devices, and if a registry key really *is* no longer necessary, what is the real harm in leaving it alone? Hint - if it's not doing anything, a few bytes in the regstry (even thousands of them, in the worst case) aren't really worth troubling with.

registry cleaners are unnecessary and should be avoided , its just tweaking for tweakings sake

They had a use in the Windows 95/98/ME days, when system resources were limited, and memory was expensive, and when a badly written app could hose the whole OS.

Microsoft even published its own Registry Cleaner utility made specifically for Windows 98 and Windows Me, and there was a registry backup feature built into the OS, but this has not been repeated for XP or any NT system since

beauparc said:

Does it do any good? No, I don't think it does.

Agreed - I wonder many times what people are hoping to achieve by "cleaning" their registry other than scratching an OCD itch.

If you're doing anything to your Windows installation that would reasonably require "having a backup first" and it's not a major kernel update or service pack, you probably shouldn't be doing it . That's really all the advice anyone should need.