RegCreateKeyEx succeeding, but no key added - c++

Question

I am trying to get into C++ programming on Windows for reverse engineering purpose, and I am stuck trying to had a Windows registry key. The functions RegCreateKey and RegSetValueEx are returning ERROR_SUCCESS, but the key is missing when checking the registry.
Here is the code:
void AddRunKey() {
wchar_t subkey[512];
wchar_t cmd[512];
wcscpy_s(subkey, L"Test");
wcscpy_s(cmd, L"%windir%\system32\cmd.exe");
HKEY runKey;
long res;
res = RegCreateKeyEx(HKEY_CURRENT_USER, L"SOFTWARE\\Microsoft\\Windows\\CurentVersion\\Run", 0, NULL, 0, KEY_ALL_ACCESS, NULL, &runKey, NULL);
if (res != ERROR_SUCCESS) {
std::cout << "fail\n";
}
res = RegSetValueEx(runKey, subkey, 0, REG_EXPAND_SZ, (BYTE*)cmd, wcslen(cmd) + 1);
if (res != ERROR_SUCCESS) {
std::cout << "fail\n";
}
RegCloseKey(runKey);
}
int _tmain() {
AddRunKey();
}
I compiled it on Visual Studio, release mode, 64 bits on a Windows 10 - 64 bits virtual machine. No errors are returned when running the code.
When opening the Windows registry editor, under HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run, the key cannot be found
What is causing this behavior ? How can I fix it ?
EDIT (updated the key path): RegCloseKey returns 0

Answer 1

I see several mistakes in your code.
You need to escape the \ characters in your file path.
You misspelled CurentVersion in the key path. It needs to be CurrentVersion instead.
You are calling RegSetValueEx() and RegCloseKey() unconditionally whether RegCreateKeyEx() succeeds or fails.
You need to specify the value size in the last parameter of RegSetValueEx() in bytes and not in characters.
Try this instead:
void AddRunKey() {
wchar_t subkey[512];
wchar_t cmd[512];
wcscpy_s(subkey, L"Test");
wcscpy_s(cmd, L"%windir%\\system32\\cmd.exe");
HKEY runKey;
long res = RegCreateKeyEx(HKEY_CURRENT_USER, L"SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Run", 0, NULL, 0, KEY_SET_VALUE, NULL, &runKey, NULL);
if (res != ERROR_SUCCESS) {
std::cout << "fail\n";
}
else
{
res = RegSetValueEx(runKey, subkey, 0, REG_EXPAND_SZ, (BYTE*)cmd, (wcslen(cmd) + 1) * sizeof(cmd[0]));
if (res != ERROR_SUCCESS) {
std::cout << "fail\n";
}
RegCloseKey(runKey);
}
}
int _tmain() {
AddRunKey();
}