The RAM in your computer is short term memory, which is cleared when you restart the computer. The Registry in your operating system is the long term memory of the operating system. The Registry Editor helps you to make manual changes to this memory.
Have you used the Registry Editor before? If not, it's a scary tool, but it's pretty simple once you get used to it. Read Annoyances: Introduction to the Registry.
As an example, say you need to Change or to Delete the Value NodeType in Registry Key [HKEY_LOCAL_MACHINE\ System\ CurrentControlSet\ Services\ Netbt\ Parameters], as instructed separately.
HKEY_LOCAL_MACHINE\ System\ CurrentControlSet\ Services\ Netbt\ Parametersis called the Registry Key. The string
NodeTypeis called the Value name. And the string
1, 2, or whatever (entered as a DWord)is called the Value data. My sympathy to you, as you try to absorb this. I don't find it too instinctive either.