Guys, finally I figured out that it is NOT CCleaner issue. After being there for almost a four days, today morning Windows regenerated the "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters" branch & I lost the REG DWORD "DisabledComponents" once again. It looks like, 1903 is doing something different than previous versions, forcing IPV6 to refresh something (beyond my understanding), which regenerates the entire "Parameters" sub-key branch.
Thank you to everyone who took the efforts to respond. I have raised a question with Microsoft Answers and hoping to get some answers. Interested could follow the thread here.
https://answers.microsoft.com/en-us/windows/forum/windows_10-networking/windows-10-1903-disabledcomponents-registry-key/93c9ca80-ff4e-4af5-9f7a-2e9bcec6c17d?tm=1560239135300