A long time ago, in a land forgotten by time (before Microsoft Windows 95), Windows computers and their programs had .ini (configuration) files that stored information. These files determined how a program ran, its environment, and a host of other things.
Then the Windows Registry came onto the scene, with each key in the registry being similar to a bracketed heading in the old .ini file and values similar to entries under the .ini headings. However, registry keys can have nested subkeys with string or binary data that .ini files don't support. Does the registry periodically need cleaning? Let's take a look.
Hives and keys?
A registry hive is a group of keys, subkeys, and values in the registry that has a set of supporting files that contain backups of its data. The registry has gone through very little changes, so if you're interested in learning more about it, check out "What's all the buzz about registry hives?"
If you're not too familiar with the registry and how it works, there are a slew of different companies that would like to sell you a registry cleaner. Do you need to clean your registry? Let's look at the facts.
What registry cleaners claim to do
What do registry cleaners claim to accomplish? Well, some of them claim to reduce the size of the registry and remove orphaned entries to speed up Windows. Sure, removing orphaned entries will reduce the size, but today's hard drives have gigabytes of free space and 10 MB isn't going to make a difference.
Besides, no one can give you a benchmark telling you how much speed you'll gain. The reason they can't tell you how much faster your system will run is because the size of the registry has nothing to do with the speed at which your machine operates.
The .ini files are flat text files, which require sequential searching. Registry files are database files, complete with indexing. If the index is up to date — and the system rebuilds it after each change, so it probably is — then size makes no difference.
Other registry cleaners say they'll remove invalid registry entries that can cause errors in other installed programs. Programs keep registry entries in their own keys and rarely reference keys written by other programs. They also include an uninstall routine that deletes the entries when you remove the program.
Many older programs may not work this way, and maybe some of today's programs don't do the best job of clearing their entries. However, the system will never reference the data that they leave behind.
Some registry cleaners claim that they correct problems with Windows crashes and error messages. I've been an administrator on Windows machines since NT 3.5, and I've never traced a crash or error message to the registry — nor have I met any administrator who has.
Finally, some registry cleaners say they remove entries pointing to nonexisting files that are invalid and require deletion. If a registry entry points to a file that's no longer present, of course you can delete them. However, if an entry points to something that doesn't exist, then the system will never use it. Do you delete every unused file on your computer?
Who needs registry cleaners?
There are two types of people who possibly might need registry cleaners. The first are those people who open up the registry and make manual changes. These people know exactly what they're doing; they follow precise instructions from the manufacturer, or they just like to tinker around and see what happens. This group might need to undo what they've done and could use a registry cleaner.
The second group of people who definitely need to clean their registries are programmers and developers. During the development of a program, you might go through hundreds of install/uninstall routines. It's important to ensure that you're working with a clean machine to make sure previous problems don't interfere with the latest version of your software.
If you're a developer or someone who fiddles with the registry, then by all means find yourself a good registry cleaner. As for the rest of us, leave the registry alone, and don't buy into the hype of needing to clean your registry.
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