Windows XP control panel - providing a value for the "comments" field - windows-xp

Question

Where does the Windows XP control panel get the value for the "Comments" field from? I'm writing an EXE control panel application, and it doesn't appear from the documentation that you can provide a value for that field.

Answer 1

Registering an Executable File (exe) as a Control Panel Applet on Windows Vista using Windows Installer XML (WIX) at Link
[previous answer]
See the Executable Control Panel Item Registration of Registering Control Panel Items at http://msdn.microsoft.com/en-us/library/cc144195(VS.85).aspx
Specifically, you want InfoTip, which is the comments.
Registering Control Panel Items
Control Panel items must be registered
in order to appear in the Control
Panel window. If the Control Panel
item is implemented as part of a .exe
file then it is registered as a
command object. Registration differs
if the item is implemented as a .dll
file that exports the CPlApplet
function.

Answer 2

Using CPLApplet:
When Control Panel loads a .dll (or
.cpl) file, it calls the CPlApplet
function to get information such as
the number of Control Panel items the
file hosts, as well as information
about each item.
When Windows first loads the Control
Panel item, it retrieves the address
of the CPlApplet function and
subsequently uses that address to call
the function and pass it messages. It
might send the following messages.
You need to handle CPL_INQUIRE Message and fill the CPLINFO Structure.
typedef struct tagCPLINFO {
int idIcon;
int idName;
int idInfo;
LONG_PTR lpData;
} CPLINFO;
idInfo is the resource identifier of the string containing the description. You cannot simply set this thing by filling in some registry key.
Edit: Ok, my bad, this is an old solution.

Answer 3

This string is retrieved from the HKCR\CLSID{guid}\InfoTip registry value. How to whack the registry into shape is explained very well in this MSDN Library article, not much I can add to that.