I am getting error 2 in my winreg function - c++

Question

My code:
HKEY hKey;
char *path = "SYSTEM\\CurrentControlSet\\Control\\IDConfigDB\\Hardware Profiles\\0001\\HwProfileGuid";
LONG result = RegOpenKeyExA(HKEY_LOCAL_MACHINE, path, 0, KEY_ALL_ACCESS, &hKey);
QString q = QString::number(result);
if (result == ERROR_SUCCESS) {
QMessageBox messageBox1;
messageBox1.critical(0,"Error", "Success");
messageBox1.setFixedSize(500,200);
} else {
QMessageBox messageBox2;
messageBox2.critical(0,"Error", q);
messageBox2.setFixedSize(500,200);
}
The error I am getting:
Where the key is in my Registry:
I think the problem is related to the way I put the info in the path variable, but I am not sure.

Answer 1

You have HwProfileGuid in the wrong place.
HwProfileGuid is a value inside of the 0001 key, but you are trying to open HwProfileGuid as a sub-key of 0001 instead, which is why you are getting error 2 (ERROR_FILE_NOT_FOUND), because there is no sub-key named HwProfileGuid.
Also, KEY_ALL_ACCESS is too many rights to request just to read a value from a key. Use KEY_QUERY_VALUE instead. Don't request more rights than you actually need.
Try this:
const char *path = "SYSTEM\\CurrentControlSet\\Control\\IDConfigDB\\Hardware Profiles\\0001";
const char *valueName = "HwProfileGuid";
char guid[40] = {0};
HKEY hKey;
LONG result = RegOpenKeyExA(HKEY_LOCAL_MACHINE, path, 0, KEY_QUERY_VALUE, &hKey);
if (result == ERROR_SUCCESS) {
DWORD size = sizeof(guid);
result = RegQueryValueExA(hKey, valueName, NULL, NULL, reinterpret_cast<LPBYTE>(guid), &size);
RegCloseKey(hKey);
}
QMessageBox messageBox;
if (result == ERROR_SUCCESS) {
messageBox.critical(0, "Success", guid);
} else {
messageBox.critical(0, "Error", QString::number(result));
}
messageBox.setFixedSize(500, 200);
Alternatively, you can use RegGetValueA() instead of using
RegOpenKeyExA()+RegQueryValueExA():
const char *path = "SYSTEM\\CurrentControlSet\\Control\\IDConfigDB\\Hardware Profiles\\0001";
const char *valueName = "HwProfileGuid";
char guid[40] = {0};
DWORD size = sizeof(guid);
QMessageBox messageBox;
LSTATUS result = RegGetValueA(HKEY_LOCAL_MACHINE, path, valueName, RRF_RT_REG_SZ, NULL, guid, &size);
if (result == ERROR_SUCCESS) {
messageBox.critical(0, "Success", guid);
} else {
messageBox.critical(0, "Error", QString::number(result));
}
messageBox.setFixedSize(500, 200);

Answer 2

Dont pass Computer\\HKEY_LOCAL_MACHINE to the string. just SYSTEM\\CurrentControlSet\\Control\\IDConfigDB\\Hardware Profiles\\0001 Because HKEY_LOCAL_MACHINE are exist in RegOpenKey First Parameter. And dont try to open the value of key just the key RegSetKeyValue() For writing value of key
here the working code:
HKEY hKey;
LONG result = RegOpenKeyExA(HKEY_LOCAL_MACHINE, "SYSTEM\\CurrentControlSet\\Control\\IDConfigDB\\Hardware Profiles\\0001", 0, KEY_ALL_ACCESS, &hKey);
cout << result << "\n";