The registry is the central repository, or source, for settings on the Windows Platform. Many different programs leave their mark in the registry, keeping their internal settings in it. It's a source of much ire for many Windows users because with all of the installing and un-installing of programs, some entries become unnecessary and some overwrite necessary entries. That said, if you treat it properly and keep it maintained, you will likely have no problem with it.
The registry is easily accessible. Go to your Start Menu and then click Run and then type in regedit.exe and click Okay.
While your hard drive has folders and files, the registry has Keys and Values. Keys are just like the folders and Values are just like the files and they operate like you would think they should. The Keys are used for organization of the Values and the Values hold the real information in the registry.
There are five types of Values that can be edited with regedit:
String (REG_SZ)
This type of Value is can usually be read and edited with ease. You will find plain text within this type of Value.
Binary (REG_BINARY)
The type of Value is in raw binary data and is often hardware componenent drivers and the like. It is not too often that you will be editing one of these.
DWORD (REG_DWORD)
A DWORD Value is a 4 bit number and is often used for boolean, or 1=On, 0=Off, data.
Multi-String (REG_MULTI_SZ)
As the name suggests, this type of Value allows for a list of strings. Each string is separated by a NULL character.
Expandable String (REG_EXPAND_SZ)
This type of Value contains a variable that can be replaced when called by an application. For example, for the following value, the string "%SystemRoot%" will replaced by the actual location of the directory containing your Windows system files.
There are five main Keys in the registry and under these five Keys there are thousands more.
HKEY_CLASSES_ROOT
This key contains all of the information on the various file types your computer uses as well as OLE information for OLE-aware applications. When applying registry tweaks and hacks, this Key is not visited too often.
HKEY_CURRENT_USER
This Key points to the Key that is currently in use of HKEY_USERS for the current user. That is, it allows you to access the parts of HKEY_USERS that are of interest to your current user much more quickly. You will visit this Key often when applying registry tweaks and hacks.
HKEY_LOCAL_MACHINE
This Key contains all of the information about the hardware and software currently on your computer.
HKEY_USERS
This Key contains many preferences for each individual user of the computer.
HKEY_CURRENT_CONFIG
This Key, much like HKEY_CURRENT_USER, points to the Key that is currently in use of HKEY_USERS for the current hardware and software configuration so that you can access parts of HKEY_LOCAL_MACHINE that are of interest quickly.
So if you really look at it, there are only three parts of the registry, with the other two of the five parts pointing to specific parts of two of the three main parts.
While special software packages are needed to backup the registry in its entirety, you usually do not have to do that. Usually you will need to backup certain Keys of the registry.
To do this, select a Key and then go to the File menu and click Export. Save where you please and you have just backed up your registry. It is always best to make a backup of it before applying any new changes as the new changes may render certain functions of Windows inoperable.
To actually use a backup just double click on the backup file in My Computer and it will apply itself to your registry. It asks for you for confirmation first so don't worry about inadvertently clicking on it.
The registry often becomes a messy place because many programs do not remove themselves properly and others throw entries all over the place.
To clean the registry, you will most likely need a third party tool to do just that. I recommend TweakNow RegCleaner 2.6.5. It is free and works well. You can try other applications that do the same things but make sure that they come from reputable download sites and donâ??t install spyware and other bugs on your computer.
Always backup your registry before cleaning it, some of these programs that claim to clean your registry do more harm than good.
There you have it, a complete guide to using and editing the registry. I hope this guide proved useful in helping you understand the registry a little better. If you have any questions at all, please don't hesitate to post in our friendly forums.