In the normal course of things, an average PC user will rarely be aware of the registry. When you’ve just installed new software, you may have seen a message flash onto your screen: “updating registry, please wait”. That is about as much as you want to know: on a healthy PC the registry should work quietly in the background.

In its hierarchical database structure, it records all the hardware and software settings and parameters as well as all your personalized settings in main divisions called hives, each taking a different kind of information. One records the settings related to the actual computer, another the details of the various users of the machine, while yet another stores the preferences for each particular user.

The hives function like folders, gathering the actual information in what are called keys. The top level ones mostly function like folders as well, containing sub-keys – a structure which can be repeated until the final set of sub-keys, which actually carry the data.

Windows runs through the registry every time it starts up, conveniently finding all the settings it needs in one place. But every time a setting is changed or software is uninstalled, unused keys can be left behind. On a simple level, this means that there are useless bits of information to be read and processed.

More damagingly, conflicts can creep in and your PC can start to misbehave. This is where getting hold of a registry cleaner like Uniblue’s RegistryBooster becomes an important investment in your PC’s future health.

Each time an installer for an application program is executed, additions are made to the Windows registry. This can result in increased memory overhead both when the PC boots at start up and also in operational use, causing the dreaded PC slow downs as time passes and the user installs more and more application software.

Most users try to counteract this effect by uninstalling specific applications which are no longer required. However, applications which have poorly coded uninstallers, or do not have uninstallers altogether, can leave entries in the registry – the term “Software Rot” refers to the process which occurs as the PC registry fills up with possibly malformed and unused entries. In addition to this, over time the PC registry becomes fragmented, meaning that it is stored in different parts of the system hard disk, resulting in increased disk I/O and CPU cycles each time reads/writes to the registry are required.

The consequences of Software Rot are system slowdown, increased boot up times and system instability. Tools are available with the Windows operating systems such as regedit.exe and regedit32.exe which allow manual editing of the registry, however this is not something for the faint hearted! The registry’s sheer complexity makes the use of specialised registry cleaners essential, such as Uniblue’s RegistryBooster, which operates by performing a deep scan of the registry, checking for errors, correcting fragmentation and ensuring optimal PC performance through regular scans which keep the registry in tip-top shape

With use, the registry gets cluttered fast and this deteriorates the system’s performance, increasing the frequency of system errors. This is called fragmentation. A skilled user can manually edit and streamline the registry by using a Windows built in program called Registry Editor (regedit). Incorrect adjustments of registry values will result in errors associated with the running of the edited application values.

The registry is prone to corruption by other factors such as malware causing system instability and possible data loss. Common registry errors might be caused by corruption to the registry by physical means, such as hard drive bad tracks located on parts of the file. Other errors are encountered during Windows start-up, with incorrectly un-installed programs leaving entries in the registry that call them up at boot time, sometimes bringing up the common ‘missing .DLL files’ dialog boxes.

Other errors are ActiveX/COM errors, again caused by invalid object entries in the registry and can cause system crashes and data loss. Less common errors refer to missing or corrupt FONT entries in the registry, usually called up by word processors. The internet is a major source of dubious applications that install on the system without warning and wreak havoc on the registry, most of these being spyware and malware. By regularly using a registry optimizing program, the risk of losing valuable information through registry corruption is greatly minimized.

The problem is that the registry is prone to errors. Every time you change a preference, the relevant entry in the registry is changed. Every time you install a piece of software, new keys are created, to be removed once you uninstall it.

This is where errors creep in. Uninstalled software sometimes leaves unused keys behind, changed settings cause fragmentation of the registry and the effect is a large, unwieldy registry containing dud information or, worse, conflicting settings.

Registry cleaners are designed to tune your PC and keep it purring healthily under the bonnet. There are a lot of them about, but we are talking about the health of your PC here. It pays to use a reliable tool like Uniblue’s registry cleaner. The problem with much of the free software out there on the web is two-fold – first, the processes for the detection of invalid keys is often over-cautious, mis-categorizing perfectly valid keys as problems.

Secondly, most of the free cleaners do not defragment the registry. This means that Windows will take a long time to work through the settings, slowing the PC down. Worse, a number of the free cleaners have been used to carry malware and viruses, taking advantage of their access to the core of the operating system to slip a nasty payload in.

So to keep your registry healthy and your PC running at peak performance, choose a reliable utility like Uniblue’s RegistryBooster which not only keeps your PC optimized and your registry defragmented, but also keeps it safe by taking backups before it makes any changes.

The centrality of the registry promotes it as the ideal target of malware (malicious software). Both spyware and viruses are forms of malware; the former created with financial objectives in mind, the latter merely the work of vandals. These harmful forms of software are sneakily installed in a computer system without the user’s knowledge, let alone permission.

So, what problems can malware cause in a registry?

What any user must bear in mind is that such software is self-preserving; it tampers with the registry tools to cover its own tracks. Ultimately, the unsolicited software becomes to all intents and purposes another user of your system which is sending your personal information and your surfing habits to remote locations.

Additionally, the malicious software produces extra toolbars, links and favourites. It changes the registry settings of the user’s default home pages, the web browser and the mouse pointers. The user ends up tumbling on extraneous sites other than the ones he or she desires to open. And definitely, the annoying pop-ups (especially for advertisements) increase.

Both spyware and viruses run their own executable files (.exe), substantially slowing down a PC. Furthermore, they may modify system file associations and compromise proper opening of the user’s legitimate executable files causing frequent seizures or worse; prevent a PC from either booting up or shutting down properly.

Problems with the registry are easier to avoid than to solve, a registry cleaner is a friendly tool that helps to maintain the backbone of your system in shape.