Welcome, Digg visitors. Wow, twice in three days an old post of mine gets picked up and Dugg like crazy. Just to be clear: If you have a specific problem with removing a specific program, a registry cleaning utility might be able to identify keys that will help you solve that specific problem. But that’s a rare scenario. Most people I know use registry cleaners as part of their magic cleanup routine, and I see very little upside and a lot of potential downside in this sort of routine use. Specifically, as I write below, I have never seen any evidence that routine “cleaning” of the registry has any positive effect. I stand behind that statement.
Via Matt Goyer, John Hoole offers this cautionary tale:
just a note to say if you have Windows XP Media Center Edition 2005 (probably all versions actually) steer clear of registry clean programs such as Reg Mechanic they go through your registry and delete unnecessary keys….. sounds good but it didn’t count on Media Center I ran it a few days back and when I came to use Media Center it loaded then produced a crash report and died, took me ages to figure it out until I came to run Reg Mechanic again and realized This program deletes DLL files too so….. I restored the first backup and rebooted and media center worked fine so if you have that error on startup that’s your problem right there. Just restore the backup from Reg Mechanic. So you have been warned.
I’d go a step further: Don’t run registry cleaner programs, period. I won’t go so far as to call them snake oil, but what possible performance benefits can you get from “cleaning up” unneeded registry entries and eliminating a few stray DLL files? Even in the best-case scenario the impact should be trivial at best. Maybe a second or two here and there, maybe a few kilobytes of freed-up RAM, and I’m being generous. How can you balance those against the risk that the utility will “clean” (in other words, delete) something you really need, causing a program or feature to fail?
If anyone has done any serious performance testing on this class of software, I’d be interested in seeing it. In the absence of really rigorous testing and fail-safe design, I say: Stay far away from this sort of utility.
If you have a counter-argument to make, leave a comment. But simply saying, “I use Reg-o-matic Deluxe and my computer is way faster than ever!” isn’t good enough. Show me the data!
Update: I did a Google search for “registry cleaner” performance tests, and got more than 25,000 hits. In the first 15 pages, however, there wasn’t a single example of an actual performance test. Virtually all the results were from companies that make and sell this sort of utility, or from download sites that have affiliate agreements with these developers. I found one recent how-to article from Ed Tittel on TechWeb. Ed asserts that “Most Windows experts recommend a Registry clean-up on all systems at least once every six months.” He didn’t link to any of those experts, however.
Later in the same article, Ed advises: “I urge you to check comparative reviews, ratings, and rankings of Registry Clean-up Tools before you invest hard-earned dollars on these products.” Sadly, there are no links here either. I suspect that’s because detailed comparative reviews of this class of software don’t exist. Ironically, the article inadvertently documents the case against this sort of utility. Early on, it states: “The typical Windows system has literally hundreds of thousands of Registry entries.” The screen shot from the free utility he spotlights shows a grand total of 19 “errors,” most of which are simply pointers to CLSIDs that don’t exist. Is it really worth spending hours on this task? I don’t think so.
The best bit of reading I found in my search was this rant from a poster named Jabarnut on a thread at DSL Reports’ Software Forum:
The Registry is an enormous database and all this “Cleaning” really doesn’t amount to much…I’ve said this before, but I liken it to “sweeping out one parking space in a parking lot the size of Montana” … a registry “tweak” here and there is desirable or even necessary sometimes, but random “cleaning”, especially for the novice, is inviting disaster.
I also would like someone to show me any hard evidence that registry cleaning actually improves performance. (Unless there is a specific problem that has to be addressed by making changes to the registry).
Sorry to go on like this, but I feel there is way to much Registry “Cleaning” going on these days just for the sake of “cleaning”.
Amen.
Update 11-Sep: Several commenters have made a good case for a handful of utilities that include registry repair and cleaning options. They make the point that these are useful when used intelligently, not indiscriminately. My colleague George Ou from ZDNet passed along these comments:
I do like the free CCleaner. I’ve cleaned out 1 GB or more of junk on friends computers and it does make the system a little more responsive. You don’t get as many unexplained pauses. This is a problem with the lack of multithreading in Windows Explorer most of the time when it times out on dead resources like a detached network drive. I thought I remember reading something on the Vista features that fixes this by supporting multiple threads.
Other than that, I’ve made sure that I don’t have any dead links the system is trying to access on the desktop that are sure to cause a 30 second lockup even if I drag an icon across the dead link icon. Ccleaner also does a nice job removing a lot of that junk. The combination of MSCONFIG and Ccleaner works wonders.
OK, I’ll give it a try.
Ed: I used to be a big sucker for various registry cleaners, but essentially learned the hard way that what you say about them is absolutely correct. In fact, the only one I have ever used that didn’t eventually wreck my system at least once (did you mention Registry Mechanic? Grr!!!!) was Registry First Aid (which is also the safest — it forces you to create a restore point, and it also automatically creates backups of all registry changes).
I have used RFA enough to conclude that if used correctly (and if you choose the changes manually) it does my system no harm, but whether it results in any transparent performance gains (much less gains that justify the time one must spend running, maintaining, and updating the program) is a totally separate question.
Ken
I used System Mechanic and performed a clean up .
I then decided to run a function called ‘defrag registery files’ My OS system crashed completely, refusing to boot to windows.
I was using my daughter’s PC and was totally embarrassed. Worse still, there was no win xp disk in the house.{possibly not supplied as it was a HP}
I was required to return to my daughter’s house the following week and had to drive a total of about 300km with my version of win xp.
I convinced MS activation to give me a new activation code ..which he eventually he did just to, perhaps, get me off his case!
An email to System Mechanic for help was not returned.
I use to regularly use an older version of System mechanic on Win 98 and had no problems …although I did not actually by a copy ..just used the free trial. Performance improvements were difficult to tell, although it did not do any harm.
So as usual ..buyer beware. Like many fuel and oil additives regularly touted, many pc utilities only enhance performance psychologically ..or so it would seem
jp
I used to clean the registry occasionally, too, but after using Total Uninstall, it completely removes all the entries a program installs to the registry, which solves my problem with these cleaners.
I’ve used RegScrubXP and Easy Cleaner without problems.. as well as NTREGOPT to “defrag” the registry. Haven’t had problems in the past 2 years of usage. It’s helped with some spyware removals on other people’s machines..
But I can’t back any of this up with factual data
Is this a case of obsolete folklore? Does anyone know if the Windows 95 or 3.1 registry had a size limit or was poorly implemented for large sizes? Or was this NEVER a useful tip?
Gary, that’s an excellent question, and I think you’ve nailed the source of this category. The size and integrity of the registry were indeed an issue in the Windows 9X days, when system resources were limited, memory was relatively scarce, and a badly written app could hose the whole OS. In fact, Microsoft 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. They’ve never published an equivalent tool for Windows XP (or any NT-based OS).
I have to agree that registry cleaners do little good at best and can occasionally do a lot of harm. Not a trade off that seems worth it.
On the the other hand, how full of old crud does the registry fill up with? It seems like Windows does get slower over time with adding and removing programs although I don’t have any hard data. The registry seems like a very poor concept, basically a huge dumping ground that runs your system that you have to rummage thru and hope you find a problem. Not worth it at best and not worth the books on tweaking your registry either.
What’s needed is a registry manager, something that clearly organizes personal preferences, systems settings and the rest of the junk that apps throw in.
I’m actually really annoyed with this issue. On my Win98 machine I have this great little program called TestRun by BB. It makes a dummy copy of your registry and user files and puts your computer in test mode with them. Then you can fool around all you want and put your computer back to exactly the state it was in before you screwed everything up. It really works nicely too. I can also switch back and forth between the configurations.
You can make various copies to restore too. I like to make a nice copy of my freshly reinstalled OS with my well-tested installed just how I like them. Then when I get really fed up with Window’s shinanigans I just restore that copy. It’s exactly like a fresh reimage.
WinXP just won’t give up that much control. In fact when I have used Total Uninstall lately and it doesn’t do much good. I also used Windows own restore function and my system is pretty screwed up now… a week after reimaging. XP just does too much stuff in the back ground to be able to replace all of the settings to a day earlier. It also thinks for itself too much and makes so many changes on it’s own that we confuse it when we change old Registry entries and remove system dll’s.
It is now screwing with programs that I didn’t touch in my installations. My Symantec Virus program won’t even work now. How the heck did it delete files in the Symantec folder???
I hate computers that think for me. I am the master, it is the slave dammit, contrary to what Microsoft would have.
A product that has worked really well for me is Stompsoft Registry Repair. It kept my registry clean of Windows debris and has a nice feature set.
Very well said, Ed. I used to be a big proponent of registry “cleaning”, and recommended it as a first line of troubleshooting. But after seeing first hand the many problems that can be caused and exacerbated by these “tools”, I now only recommend them as the very last resort before wiping and starting over.
I really don’t like using or want to use a Reg cleaner. But I’ve got one of those rare instances where windows issues me an error message about something missing in the reqistry that cannot be verified. It causes my system to reboot. It behaves like a virus, but the three different virus scanners and programs don’t find anything. I’m left with using a Registry Cleaner. And they have already messed with some of my programs activation codes, which I now must go find again! ;-( Bad idea in my mind.
Regclean and Regmaid were designed to clean programmers machines. Typically each build (at least in VB)generated new clsids which meant one project could generate zillions of one use registry entries. It wasn’t meant to be used as an end user cleaner.
Q156078
I am taking your advice and not bothering with a registry cleaner. However, I find it ironic that your commentary is accompanied by so many ads for products you wouldn’t use and are advising against!
I find it more obnoxious than ironic. Unfortunately, Google doesn’t offer very good tools for blocking ads that a client (that would be me) finds objectionable. Most of the Google ads on this site are worthwhile and legitimate. But when I wrote about spyware, or registry cleaners, or Windows performance, a whole class of ads appear that can best be called snake oil. I can exclude up to 200 URLs or domains, and I use this capacity to block the worst offenders. Beyond that, I have to trust in the intelligence of my audience to not fall for snake-oil salesmen.
Yup I agree wholeheartedly. As a serious gamer I was horrifed to see my display come garbled, games running slow, with major artifacting etc. Scrated my head for days. Dxdiag reported that everything was fine. I even thought I’s dlown up a card with my serious Guild Wars nights. Then I remembered using a registry editor. Thank god I backed up or I would have had to reformat. They suck everyone avoid them like the plague
Hi Ed. I post quite a lot on ArsTechnica forums (and read even more), and there are bunch of “real techies” who know their stuff. And one in particular (with nick DriverGuru) exposed many many of these myths; for instance regarding the “memory optimizers”, “XP tweaks” and well “registry optimizing” (deleting the orphaned keys/entrys/values)
As far as I understand it now these orphaned keys/entrys/values surely make registry hive-files (and their respective backups) unnecessarily bigger, but that (the size of the registry-files) certainly doesn’t degrade the computer’s performance per se, i.e. don’t impact the speed of registry operations (and therefore impact the overall computer’s speed) nomather how many of them were left after some program was un-installed, or how “deep” the respective key/entry/value resides in the registry structure, simply because registry queries (searching), reads and writes ARE NOT THE LINEAR PROCESS.
Here are few related threads on ArsTechnica (my nick is “shirker”)
“Keeping the registry tidy : How DO you do it ?!” (In this one DriverGuru mentions the “linear” thing)
“removing unused registry entries?”
Not related to this particular subject, but another “gem” from the very same DriverGuru guy was the one regarding the “number of running processes” thing. You see, I always thought that more things that are open/running/mapped etc. the slower the system might become. But then I was told by DriverGuru that ALMOST NOTHING IN THE SYSTEM RUNS IN NORDER-N TIME, LET ALSONE WORSE. In other words there is nothing that makes the system run slower just because there are more “things” running/mapped, like more processes, more handles, more texture-objects etc.
P.S., However, there is one program that I would recommend. It is called Registry First Aid (shortly Reg 1 Aid), from KsL Software, published by RoseCitySoftware:
http://www.infinisource.com
http://www.RoseCitySoftware.com/Reg1Aid
This one is really powerful, cause it doesn’t clean registry automatically (like I imagine most of “registry cleaners” do), but it offers users to browse invalid entries it finds, and then choose which one to fix, and how to fix them, like defferent options for paths for example, that app finds during HD scan for those string-values. This was especially useful, when I changed the “ProgramFiles” and “CommonFiles” variables with MS’s TweakUI, because Registry First Aid simply fixed all that for me (instead of doing it manually with Regedit)
Options that it offers after the scan:
“Fix entry” … fixes to the choosen “correct” entry
“Leave entry without change” … self-explanatory
“Delete entry” … self-explanatory
“Cut Invalid Substring” … for complicated values with more than one path, etc.
cheers, Ivan Tadej
________________
Below are the links to my home-site, which is generally about the important computing stuff I discovered so far in the world of computing. I’ve tried to make a site that will try to express those other practical things that you learn when you are useing your computer, i.e. I didn’t want to make a site with usual “tweaks” and security programs listed (like there are many out there), and also nothe that the emphasis is on the site’s content not the look (by default I only use HTML/JavaScript and a bit of CSS), i.e. I’ve tried to make it as simple and fast as possible, so there’s no fancy code, etc.
The three “clean” variants (with no popups, banner-adds, and W3C validated):
http://ivan-tadej.atspace.com/index.html
http://users.volja.net/tayiper/index.html
http://shirker.freehost386.com/index.html
Well, there are two others though with pretty much the same content (with only slight differences in site-code, like inner-links, host-specific banners, etc.), but I don’t list them here.
Iv just been cured of Registry ‘optimisers’!After reading your comments I decided to put it to the test.I downloaded 4 different Reg ‘optimisers’-each returned varying’discrepencies’.One advised I had 186′errors’.At the other end of the scale,another told me my registry was in an’outstanding’state.Its nonsense.Leave well alone is my advice to those who just cant resist breaking the ‘If it aint broke,dont fix it’wisdom.Thanks for freeing me!
I absolutely agree for all those registry cleaners but windows really need to clean the registry BUT in normal(without clean wrong keys and..)and safe metod AND to clean it if possuble all of the unused keys and values!I fhave found really very good tool for this “question” and it is jv16 power tools (the registry cleaner) and regsupreme(only registry cleaner).I am absolutely shure this is “one” (I will say the best) registry cleaners!!!!!!!
sometimes a bloated registry will cause problems… i do agree that most people should stay away from most registry cleaners. I do however like to manually clean my registry from all the left over keys programs like to leave.
registry supreme or rg crawler work well with that but it helps if you have an idea what you are doing.
I dont nessarily do it for performance but i am under the opinion that when you uninstall software it should remove all traces or ask if you want to keep ini files, etc but i cant stand the left directories and the forgotten reg keys.