Thread: Want to run .dll when a program is started

I only have C console programming experience.
But i would like to make a .dll that i can put in my c:\windows\system32 folder.

As everytime i open my calculator my numlock goes off.

I would like the .dll to start when calculator is opened, wait for 2 seconds, then check if the numlock key is active, if it isn't press it down.

I have been looking up info about global hooks, but can't seem to make heads or tails of it.

Anyone have some ideas or code they can through at me?

Thanks.

I use Borland C++ 3 Biulder on Win XP

1. Rename calc.exe to calc_old.exe
2. Create a new program named calc.exe

Code:

int WinMain(...)
{
    ...

    CreateProcess("calc_old.exe", ...);
    WaitForInputIdle(pi.hProcess, 3000);

    // Activate num lock...
    ...
}

3. Copy your new program (calc.exe) to "c:\windows\system32".

ok i can get that to work, but id like to put it in a .dll if possible, as i would like to apply it to other prorams when they are started

There are a few options:

• Use the AppInit_DLLs registry value. This will load your dll into every process. This may slow down your computer.
• Wait until calc starts and then set a hook on its main thread (pi.hThread). The type of hook does not matter as we are just using this method to get our dll loaded in the calc process.
• Wait until calc starts and insert the dll using CreateRemoteThread. This is done by using LoadLibrary as the thread procedure. There are examples on this board and the web. I recommend using no. 2 rather than this method.
• Alter calc.exe so it links with your DLL.