HoW To Set registry value in HKLM using c programm

i new in program , i need help,, how to add registry value in HKLM.

this is my code

Code:

#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
int main()
{
    HKEY hkey;
    LONG lreg;
    LONG lres; 
    DWORD dwvalue = 0;
   
    printf("change registry key \n"); 
    
lreg= RegCreateKeyEx(HKEY_LOCAL_MACHINE, /* reg key */
               "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Authentication\\LogonUI\\Background", /* key to set */
               0,NULL,REG_OPTION_VOLATILE,KEY_ALL_ACCESS,
               NULL,&hkey,NULL); 
               if(lreg ==ERROR_SUCCESS) {
                       printf("success\n");}
               {
                      
                       lres = RegSetValueEx(hkey,"whatever",0,REG_DWORD,(BYTE*)&dwvalue, sizeof(dwvalue)); /* what ever just trying only */
                     
                    if(lres ==ERROR_SUCCESS){
                            printf("sucess"); 
                            }
                      }
                     
               
  RegCloseKey(hkey);
  system("PAUSE>nul");    
  return 0;
}

please help me

Maybe you would learn more if you also printed out the ERROR paths, as well as the error codes.

"success" or a blank screen are hardly informative.

this program can print successfully but the registry does not have the value.

Are you sure the key hasn't been changed? If you're looking at it with RegEdit, make sure you hit refresh (in the view menu I think). If it really hasn't changed, maybe you don't have access.

Originally Posted by oogabooga

Are you sure the key hasn't been changed? If you're looking at it with RegEdit, make sure you hit refresh (in the view menu I think). If it really hasn't changed, maybe you don't have access.

yes the value does not change. if i chnge HKLM to HKCU it's working,, but i wnt change at HKLM.

Are you creating a 32bit application and running it under 64 bit? If yes you will have to access it through the subkey 'Wow6432Node', that is "SOFTWARE\\Wow6432Node\\Microsoft\\.."

Hope that helps
Niara

Originally Posted by Niara

Are you creating a 32bit application and running it under 64 bit? If yes you will have to access it through the subkey 'Wow6432Node', that is "SOFTWARE\\Wow6432Node\\Microsoft\\.."

Hope that helps
Niara

Thanks for helping Niara.