un exemple avec les MFC :
#include "Atlbase.h"
CRegKey myKey;
if (myKey.Open(HKEY_LOCAL_MACHINE, "Software\\Katarn Corp.\\K-HL" ) == ERROR_SUCCESS)
{
unsigned long lng = 255;
path.GetBufferSetLength(255);
myKey.QueryValue(path.GetBuffer(255) ,"Path",&lng);
path.ReleaseBuffer();
myKey.Close();
}