The Windows Registry is a large database that stores all the information and settings for all the hardware, software and PC preferences. When a user makes changes to a Control Panel settings, or File Associations, or installed software, the changes are reflected and stored in the Windows Registry. Everytime a change takes place, the registry is updated, and information is added to it. However this leads to the registry grows bigger with passage of time, slowing down your PC. The more software programs you install and de-install, the bigger your registry will grow. This leads to weaker computer performance and even worse, it can can cause crashes and blue screens. Optimizing your registry can improve your computers performance greatly, and it helps preventing and can solve computer problems. The manual cleaning of the Windows Registry is extremely complex and should only be performed by an expert. If done incorrectly you can seriously damage the Registry, which may result in bluescreens, your computer not booting anymore or data loss. Instead you can go in for a good registry cleaner, which would help solve all your problems. Just to give an overview of what windows registry looks like and how to get in there, read through.. The Registry information is stored in 2 hidden files in your Windows\System directory, system.dat and user.dat

1. HKEY_CLASSES_ROOT: stores information about registered applications, such as file associations, tying them to the applications used to handle these items. This subtree contains two types of data: a) Data that associates file types with programs. The file type subkeys here have the same name as the file name extension example .exe File type associations are stored in the registry, but you should use Windows Explorer to change them. (In Windows Explorer, from the Tools menu, click Folder Options, and then click the File Types tab.) b) Configuration data (exampe for Visual Basic programs) 2. HKEY_CURRENT_USER: This subtree contains the user profile for the user who is currently logged on to the computer. The user profile includes environment variables, personal program groups, desktop settings, network connections, printers, and application preferences. This subtree does not contain any data but provides easier access to the data. 3. HKEY_LOCAL_MACHINE: This subtree contains information about the local computer system, including hardware and operating system data, such as bus type, system memory, device drivers, and startup control parameters. 4. HKEY_USERS: This subtree contains all actively loaded user profiles. It has atleast 3 keys: a) DEFAULT, which stores the profile used when no users are logged on to the computer (such as when the CTRL+ALT+DELETE logon prompt is displayed). b) A subkey named for the Security Identifier (SID) of the current local user. This subkey contains the current user's profile. If the user is logged on remotely, the data for the user's profile is stored in the registry of the user's local computer. c) A subkey named for the Security Identifier (SID) of the current local user with the _Classes suffix. This subkey contains the current user's Classes. 5. HKEY_CURRENT_CONFIG: This subtree stores configuration data for the current hardware profile. This subtree does not contain any data. It just stores a pointer to the content of the Hardware Profiles. The folders inside Windows Registry window denote: 1) Open/selected folder: as you see in Windows Explorer 2) Closed folder: as you see in Windows Explorer 3) String Value: allows you to place certain values to certain aspects of a program such as a version number. 4) Binary Value: allows you to set attributes to a particular application, values are in binary.5) Dword: Similar to the binary value allowing you to set attributes; however, are done in binary and hexadecimal.