Working with Windows Registry

Hello there.
Simple answer is no - you can't add an xml file to the windows registry... at least not in the way you are thinking.
What you can do is add the xml file content to the registry, as a string value. For such a task, using RegSetValueEx is the way to go:
1) Read the content of your xml file into a variable;
2) Use the xml content for the lpData parameter of RegSetValueEx - you may need to perform casting.

But here's the rub: the registry is not designed for large pieces of data. If your xml file content is not Unicode (ANSI), you will have a maximum of about 1MB available (the limit of the REG_SZ value). In addition, MSDN states:
"Long values (more than 2,048 bytes) should be stored in a file, and the location of the file should be stored in the registry. This helps the registry perform efficiently."

LONG WINAPI RegSetValueEx(
  _In_        HKEY hKey,
  _In_opt_    LPCTSTR lpValueName,
  _Reserved_  DWORD Reserved,
  _In_        DWORD dwType,
  _In_        const BYTE *lpData,
  _In_        DWORD cbData
);

for d
etails visit:

http://msdn.microsoft.com/en-us/library/windows/desktop/ms724875(v=vs.85).aspx[^]

You may add the XML file logical content to the registry (since the registry has, like the XML file, a tree structure). However you must use the registry API (see the documentation)[^] to perform the task (storing content as strings).

As Richard correctly noted, you shouldn't add too much info to the registry. That is if the XML file is big then you shouldn't add its content to the registry (as suggested, you should leave the content in the XML file and store in the registry just the file path).