Unknown

It is unkownn exactly what type this entry is supposed to be. Note that it may not actually matter anyway; Applications that access the registry generally get their data from the registry exactly how it was previously written. The application would have to make decisions based on the value type for the type to matter. Data in raw binary format. Basically this is the program's way if saying it is putting this data in the registry without a care for the data's readability or the ability of anyone to deduce and exploit its used through the registry editor.

reg_binary

Data in raw binary format. Basically this is the program's way if saying it is putting this data in the registry without a care for the data's readability or the ability of anyone to deduce and exploit its used through the registry editor.

reg_dword

To the less enlightened, a number without a fraction. For the more techinically minded, a 32-bit signed integer.

reg_dword_big_endian

reg_dword_little_endian

A search through the MSDN library didn't seem to bring about much information about these two types. Many copies of the same table simply rewrite the indentifier in English. They are possibly used to 'tag' certain values as being one format or the other, so that computers of different architectuers in the same network can tell which is which.

reg_expand_sz

A string that contains references to environment variables between '%' characters. When values of this type are read on Windows NT, variables references are automatically expanded. On Windows 95 they are not. (check this Mick)

reg_full_resource_desriptor

reg_resource_list

reg_resource_requirements_list

Information about this type is sketchy. I believe they are NT-only. They have something to do with hardware resources, i.e. IRQ's, ports, DMA channels etc.

reg_sz

A null-terminated string.  

reg_link

A symbolic link. A search for more information on this type in the MSDN library proved futile.

reg_multi_sz

A list of null-terminated strings, laid out end-to-end, with an extra zero at the end.

reg_none

A type that doesn't mean anything. No idea what the semantic or conventional difference is between this type and REG_BINARY.

key

A key. Keys can have value data as well as subkeys. A key's value type is always the same as REG_SZ.