MsiEnumProductsEx Not Working - c++

Question

I have the following application, to check installed programs in a system:
#include <iostream>
#include <Msi.h>
#include <Windows.h>
using namespace std;
void main()
{
UINT ret;
DWORD dwIndex = 0;
DWORD dwContext = MSIINSTALLCONTEXT_ALL;
char szInstalledProductCode[39] = {0};
char szSid[128] = {0};
const char* szUserSid = "s-1-1-0";
DWORD cchSid;
MSIINSTALLCONTEXT dwInstalledContext;
do
{
memset(szInstalledProductCode, 0, sizeof(szInstalledProductCode));
cchSid = sizeof(szSid)/sizeof(szSid[0]);
ret = MsiEnumProductsEx(
NULL, // all the products in the context
szUserSid, // i.e.Everyone, all users in the system
dwContext,
dwIndex,
szInstalledProductCode,
&dwInstalledContext,
szSid,
&cchSid
);
if(ret == ERROR_SUCCESS)
{
char* name = MsiGetProductInfoEx (
szInstalledProductCode,
cchSid == 0 ? NULL : szSid,
dwInstalledContext,
INSTALLPROPERTY_INSTALLEDPRODUCTNAME
);
char* version = MsiGetProductInfoEx (
szInstalledProductCode,
cchSid == 0 ? NULL : szSid,
dwInstalledContext,
INSTALLPROPERTY_VERSIONSTRING
);
cout << name << endl;
cout << " - " << version << endl;
dwIndex++;
}
} while(ret == ERROR_SUCCESS);
}
I am using Microsoft Visual C++ Express 2010. The application is MBCS. In studio, these four things are in red (error):
MSIINSTALLCONTEXT_ALL
MSIINSTALLCONTEXT
MsiEnumProductsEx
MsiGetProductInfoEx
I linked the Msi.lib (Project properties -> Linker -> Input -> Additional Dependencies). I am just trying to figure out how MsiEnumProductsEx function works. I know there are other questions around, but I just can't understand why it isn't working because I think that I have everything for the functions to be available, at least. Thanks!

Answer 1

The MSIINSTALLCONTEXT_ALL (and related identifiers) are defined in <msi.h> only if _WIN32_MSI >= 300. You have to tell the Windows SDK what the minimum OS version you're targeting is, by defining a few macros before installing any SDK headers (like <msi.h> or <windows.h>).
You do that according to this MSDN page.
Once you've defined a suitable minimum version (looks like Windows XP SP2 and up), then _WIN32_MSI will be set to an appropriate level, and you should get the symbols.