If you had ever tried to play with Registry, you would had seen a lot of weired things in the Registry Editor. Today, I will tell you about one of the parts of the Registry Editor called CLSID. CLSID are the keys in the Registry that you would see under the key HKCR\CLSID.
These keys are associated with specific things like Operating System Processes, Services, System Folders. Now, According to Microsoft, “A CLSID is a globally unique identifier that identifies a COM class object”. There are various keys unders the key HKCR\CLSID.
If you search it, then you can get the keys of “My Computer”, “Control Panel”, “Folder OPtions” and many more to which you call the system folders. These CLSID are actually the keys to identify these system folders. For each system folder, there exist a unique CLSID. It is a 128 bit number written in Hexadecimal with curly braces in the beginning and in the end.
A CLSID contains various subkeys and values. To play with it, You need to have knowledge about it or you can create bad problems for your computer. There exists some tricks on the use of these CLSIDs, some of them I have discussed before without mentioning the name of CLSID in the posts. I will discuss more.
You can create custom CLSIDs that would referance your COM object.
For further details, you need to read the fallowing Microsoft Article