I want to restart my application on restart of the system - c++

Question

I use GetModuleFileName to get the absolute path to my application, open the RunOnce registry key using RegOpenKeyEx and set a value using RegSetValueEx.
if (RegOpenKeyEx (HKEY_CURRENT_USER,
"SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\RunOnce",0, KEY_SET_VALUE, &hk1) == ERROR_SUCCESS)
{
RegSetValueEx(hk1, // subkey handle
"", // value name
0, // must be zero
REG_SZ, // value type
(LPBYTE) &path, sizeof(DWORD)); // length of value data
RegCloseKey(hk1);
}
However my application does not start after a system restart.

Answer 1

There are a few methods:
Place your application in your start-up folder. This is a very easy method. When your system (PC) will be restarted, the application will get started (You need to login for this);
Use windows task planner;
Make the application an service.
I prefer the last option if it always needs to run. But you will need to add service handling.

Answer 2

You can create a task using Task Scheduler to run your application when the computer starts.
Open Task Scheduler by clicking the Start button , clicking Control Panel, clicking System and Security, clicking Administrative Tools, and then double-clicking Task Scheduler.‌ If you're prompted for an administrator password or confirmation, type the password or provide confirmation.
Click the Action menu, and then click Create Basic Task.
Type a name for the task and an optional description, and then click Next.
Click When the computer starts, and then click Next.
To schedule a program to start automatically, click Start a program, and then click Next.
Click Browse to find the program you want to start, and then click Next.
Select the Open the Properties dialog for this task when I click Finish check box and click Finish.
In the Properties dialog box, select Run whether user is logged on or not, and then click OK
Source:
Windows 7 - Schedule a task
PS: You must be logged on as an administrator to perform these steps

Answer 3

There are a number of things to keep in mind when using the solution you opted for:
The application does not start when the system starts but rather when the current user logs on.
If you write to the RunOnce key the operation will be performed only once. If you want your application to always start when the user logs on you should instead use the Run key.
In addition to the above, if you want to create a value you will have to give it a name. From the documentation of the lpValueName parameter for RegSetValueEx:
If lpValueName is NULL or an empty string, "", the function sets the type and data for the key's unnamed or default value.
The default (unnamed) value is the one that shows up as (Default) when using regedit. To get this to work you will have to provide a name for the value. This should be unique so that it does not conflict with other values under that key.
On a less technical note, implementing an auto-start feature for an application should only be done after thorough consideration.

Answer 4

You are passing the wrong parameter values to RegSetValueEx(). You need to use it like this instead:
TCHAR path[MAX_PATH+1] = {0}
GetModuleFileName(NULL, path, MAX_PATH);
if (RegOpenKeyEx(HKEY_CURRENT_USER, TEXT("SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\RunOnce"), 0, KEY_SET_VALUE, &hk1) == ERROR_SUCCESS)
{
RegSetValueEx(hk1, // subkey handle
TEXT("MyApp"), // value name
0, // must be zero
REG_SZ, // value type
(LPBYTE) path,
(lstrlen(path)+1) * sizeof(TCHAR)); // length of value data, in bytes
RegCloseKey(hk1);
}