Registry Files Store More than Text

[spacesurfer]

This caught my curiosity: Have you ever tried exporting a section of the registry and importing to another computer? You'll get a warning (can't remember exact message) that it's not from the same computer.

I thought, how does it know since I thought registry files were simply text files with the *.reg extension.

Then I exported a section of the registry to a *.reg file. Then I copies the text to a *.txt file and compared the size (see picture). The *.reg file is larger.

Obviously, there is more info stored in the *.reg file that the text that is displayed. I wonder if anyone knows what else is in there that causes the warning to show up.

I couldn't find anything from search.

Edited July 17, 2006 by spacesurfer

[Yzöwl]

When you export from your registry the actual exported document is encoded in Unicode, when you copy it into another document, unless it saves in Unicode by default, it will be ANSI.

ANSI encoded documents are smaller in bytes than their Unicode versions. Windows XP by default exports its registry keys in Unicode and uses a header of Windows Registry Editor Version 5.00. Win9x /NT4 versions of Windows used the REGEDIT4 header and were ANSI encoded.

To check this out, export a key from Registry Editor, in the dialog it will say

Save as type:    Registration Files (*.reg)

That is the default Unicode version.

Now repeat, using the same key but this time select

Save as type:    Win9x/NT4 Registration Files (*.reg)

That is ANSI encoded; open this file in notepad, replace REGEDIT4 with Windows Registry Editor Version 5.00 and note the file sizes.

Both files appear identical, but have different sizes!

Hope this helps quell your paranoia. 

Edited July 17, 2006 by Yzöwl

[Takeshi]

Or you could experiment with saving the txt file as unicode, which is what happens by default anyway in some localised versions of XP, like CJK.