The Windows registry in your computer is a support system for the operating system and many applications. It exists at a level even more fundamental than that of the operating system, storing important settings for low-level operating system components, as well as those of the kernel, device drivers, and third party applications.
If you were to look at your computer in very general terms as being composed of different layers arranged in a hierarchy of dependence, one viable (and admittedly grossly over-simplified) model of your computer would be the following. Items are list from most basic to most complex level of organization:
1. Physical Hardware
2. Electrical Power System
3. Windows Registry
4. Hardware Drivers
5. Operating System
6. Individual Applications/Software Programs
This arrangement can be seen a hierarchy because each item is dependent the level below it for its proper operation. As you can see, your operating system, hardware drivers and software applications all require that the Windows registry to operate properly.
How it is Structured:
The registry actually consists of two main components: keys and values. The keys are vessels while the values are the vessels' contents. Another analogy: the keys are like folders and the values are like files stored in those folders. Keys are named using a naming convention very similar to that of Windows folders you would see in the Windows Explorer application, with sub-keys under each key. This is how the registry is arranged hierarchically.
Common Problems with the Registry:
Over time, some or many of the individual registry keys can become damaged. Common causes include manual editing, malware (viruses, Trojans, adware, etc.), and frequent, normal computer use over time.
Certain Windows utilities allow people to manually edit the registry. However, errors can occur easily during the editing process and can cause serious problems with computer operation.
If you frequently download and install applications from the Internet, any one of them could contain malware which can hurt the system registry by changing settings.
Finally, mere frequent use of your computer over time can result in registry errors. Reason: every time you save or delete a file or make changes to user settings, you are causing information to be written to, read and deleted from your registry. Even computers make mistakes, and over time there can develop big holes in your registry which lead to errors.
Symptoms of Registry Errors:
Symptoms of registry errors can include any number of computer performance issues, including the inability to open certain applications, erratic behavior, and very slow startup and shutdown times.
The Need to Repair Missing Registry Keys:
Of course, for anyone with some level of computer literacy and competence, it is tempting to want to correct registry errors oneself. As mentioned above, the editing of registry keys for the purposes of repair is entirely possible. However, manual editing can actually cause more problems than it solves. Moreover, to even begin editing a registry, you first would need to know where the errors are and how to spot them. This can take even an expert some time to learn.
The best way to repair missing registry keys is to use a registry cleaner-type software. These programs are run quickly and easily and are designed for the sole purposes of finding and fixing computer registries. This is by far the safest way to repair missing keys.