Does the registry key I mentioned exist? What error does it give?
Also, as to whether or not we know it's working (assuming it's running TESV.4gb) there's not really any way I know of. I've never seen the game even get close to going over 2GB, personally.
How about getting SkyrimPath via Steampath or argument after this part if everything else fails?
HKEY regkey; if (RegOpenKey(HKEY_LOCAL_MACHINE,TEXT("SOFTWARE\\SOFTWARE\\Wow6432Node\\Bethesda Softworks"),®key) == ERROR_SUCCESS) { DWORD type; if (RegQueryValueEx(regkey,TEXT("Skyrim"),NULL ,&type,NULL,NULL) == ERROR_SUCCESS) { DWORD fnvpath_size = MAX_PATH+1; if ((type == REG_SZ || type == REG_EXPAND_SZ) && RegQueryValueEx(regkey,TEXT("Skyrim"),NULL,&type,(LPBYTE) fnvpath,&fnvpath_size) == ERROR_SUCCESS) { if (type == REG_SZ || type == REG_EXPAND_SZ) { fnvpath[MAX_PATH] = 0; if (!SetCurrentDirectory(fnvpath)) { ShowError(TEXT("Unable set current dir to Skyrim dir.")); return -1; } } } } RegCloseKey(regkey); }else if(RegOpenKey(HKEY_LOCAL_MACHINE,TEXT("SOFTWARE\\SOFTWARE\\Wow6432Node\\Valve"),®key) == ERROR_SUCCESS)...