NoteHKLM\SYSTEM\CurrentControlSet\Control\Class\
A <{Class-GUID}> subkey represents the component associated with the class-GUID.
Each <{Class-GUID}> subkey under Class represents a device class and is named by the GUID for the class. It appears as a 16-digit alphanumeric string within curly braces. These class-GUID subkeys store configuration data that applies to the entire class of devices, such as the class of all modems.
Within the class-GUID subkeys are four-digit numbered subkeys which represent particular devices that are instances of the class. These subkeys store data that applies only to that device.
Because the Class subkey is hardware specific, its contents vary widely. The Class subkey on your computer might look quite different from the attributes described in this reference.
Note
The <{Class-GUID}> subkey is a variable representing the subkeys under the HKLM\SYSTEM\CurrentControlSet\Control\Class subkey. It doesn't actually appear in the registry. This variable subkey displays the entries and subkeys that are common to many of the subkeys under the Class subkey. The actual Class subkeys in your registry depend upon the hardware installed on the computer or available to the system.
Tip
To determine the type of hardware device represented by a class-GUID subkey, use a registry editor. Click the name of the class-GUID subkey (it appears as a 16-byte alphanumeric string within brackets). The device type appears in the value of the first, unnamed entry in the subkey.
Many digits in the GUID are unique to your system. However, the three digits preceding the first hyphen are specific to the device class and are the same on all systems. For example, the three digits preceding the first hyphen in the DVD/CD-ROM drives class are always 965.
Caution
Do not change any entries in the Class subkey or any subkey within it. These subkeys are configured by the system to be compliant with Plug and Play standards. Changing any data can prevent your computer devices from starting or operating properly.