One of the main problems with Microsoft Windows (besides the issue of malware in general) is the accumulation of detritus of several types. This leads to a typical Windows installation slowing down over time, as well as potential security threats. Microsoft supplies a Disk Cleanup utility as part of Windows—but that doesn't solve the entire problem.
The Windows Registry is a well-known single-point-of-failure issue for all versions of Windows. Not only is this group of files an index to the entire Windows installation; it also stores settings, serial numbers, program keys, and individual program installation information. A cluttered, fragmented, and disorganized Registry can lead to slowdowns and weird errors. For several years, a number of companies have provided "free" Registry cleaners, but until now most of them would report, say, 800 errors--then only fix a dozen or so unless you pay for the software.
This has changed in recent times. There are now a number of free software suites that will do the job of the Disk Cleanup utility, do it better and also provide a useful Registry clean-and-repair and (in some cases) a basic malware scan. This article will briefly discuss three of these suites, along with an easy-to-use Registry-backup tool. The three suites discussed here use somewhat different techniques for checking and cleaning the Windows Registry—so running each of them sequentially works well. For safety's sake, we'll start with the Registry-backup tool.
There are those that say that Registry clean-up makes no difference in performance. I know otherwise—here's an example: I had a Windows XP PC that took ten minutes to boot up, fifteen minutes to shut down, and nearly half an hour to load the "installed programs" list. After performing the following procedure, all was well.I want to stress this important tip: before you make any changes to the Windows Registry, be it by manually editing it with RegEdit or by cleaning it with any tool, a bit of preparation is in order. I back up the Registry with a free tool called ERUNT (The Emergency Recovery Utility NT), which makes backing up and restoring the Windows Registry files extremely easy. The ERUNT package also includes NTRegOpt (The NT Registry Optimizer) a Registry optimizer which I will discuss last.
Note: ERUNT works just fine under Windows Vista and Windows 7. Just right-click the program icon and select Run as Administrator. You can make this change permanent by right-clicking on the program icon and selecting the Compatibility tab, then checking the Run as Administrator box.
I now usually start with the Comodo PC TuneUp. I use it primarily for its Registry-cleaner mode, though the other included tools are useful too.
Next is the Glary Utilities. This suite seems (to me) to be the safest for the average end user, especially in the default 1-Click Maintenance mode—it's quick, effective, and seems to not remove stuff that the user actually wants to keep.
Last on this short list is CCleaner. If you are using more than one package, I would skip the Cleaner function and go straight for the Registry Integrity part. If you do use the Cleaner, carefully look over the Windows and Applications tabs to ensure that you save (for example) your cookies, history, or anything else that you don't want to delete by checking or unchecking the appropriate boxes as needed.
Note: Users of any of these utilities will benefit from running their Registry cleaners multiple times. This is because certain Registry errors can be masked by other errors.
In summary, all users will benefit from using all three to clean the Registry, since each will find issues that the others miss.
To wrap things up after cleanup, I reboot the affected system. I then run ERUNT again to get a snapshot of the newly-cleaned-up Windows Registry. I recommend adding the letter "a" to the end of the directory name to prevent overwriting the earlier backup and to distinguish the first version from the newer version. Now it's time to run the second utility in the ERUNT package, NTRegOpt. After optimization, reboot again then use ERUNT to create a third backup of the Registry with the letter "b" at the end of the dir-name (you can delete the first two backups later, if you wish).
The overall process takes longer to describe than it does to implement, it sure beats repeated reinstallation of Windows—and it's just as effective.