You can read a key from a particular path in registry by using the RegQueryValueEx function. The following piece of code reads a particular key under HKEY_LOCAL_MACHINESoftwareDevx:
void GetKeyValue(char *key, char *retStr, int *retCode){ HKEY keyVal; long errorCode; char value[500]; DWORD size, type; *retCode = 0; strcpy(retStr, ""); errorCode = RegOpenKeyEx( HKEY_LOCAL_MACHINE , "Software\Devx", 0, KEY_READ,&keyVal); if(errorCode==0) { size = sizeof(value) - 1; type = REG_SZ; errorCode = RegQueryValueEx(keyVal, key, 0, &type,(unsigned char *)value, &size); if(errorCode==0) { strcpy(retStr, value); }else *retCode = -1; RegCloseKey(keyVal); }else *retCode = -1;}