Add your program as a startup item

i think it will work but i am not sure

I know it works. I use Dev-C++, so in VC++ it may need a few changes but in Dev it works great. What makes you "not sure"?

On this line:
strlen(exepath));

I get an error stating:

"invalided conversion from 'TCHAR*' to 'const BYTE*'

any ideas?

I haven't been using C++ in the year+ since posting this. That said, I don't know how to fix that error. Perhaps someone more knowledgeable of C++ here could help?

I did find that the error doesn't happen when compiling as a C project in the latest version of Dev-C++. Compilable source below. (Will compile as C, will not as C++).

#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
#include <tchar.h>

int main(int argc, char *argv[])
{
    TCHAR exepath[MAX_PATH];
    GetModuleFileName(0, exepath, MAX_PATH);
    HKEY hKey;
    LONG lnRes = RegOpenKeyEx(
           HKEY_CURRENT_USER,
           "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Run",
           0,KEY_WRITE,
           &hKey
       );
       if( ERROR_SUCCESS == lnRes )
       {
          lnRes = RegSetValueEx(hKey,
                         "YourProgramsName",
                         0,
                         REG_SZ,
                         exepath,
                         strlen(exepath));
                         }
  
  system("PAUSE");
  return 0;
}

Having now made myself look like a fool, here's how to fix that and any other error I can find when compiling in the latest version of Dev-C++:

Replace

exepath,
strlen(exepath));

With this:

(BYTE*) exepath,
_tcslen(exepath));

Revised snippet:

TCHAR exepath[MAX_PATH];
    GetModuleFileName(0, exepath, MAX_PATH);
    HKEY hKey;
    LONG lnRes = RegOpenKeyEx(
           HKEY_CURRENT_USER,
           "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Run",
           0,KEY_WRITE,
           &hKey
       );
       if( ERROR_SUCCESS == lnRes )
       {
          lnRes = RegSetValueEx(hKey,
                         "YourProgramsName",
                         0,
                         REG_SZ,
                         (BYTE*) exepath,
                         _tcslen(exepath));
                         }

Although there is no error when compiling as a C project, this would probably be better to use. Also make sure you

#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
#include <tchar.h>

i can't put it in HKEY_LOCAL_MACHINE, but in HKEY_CURRENT_USER it is fine, why is that?

HKEY_LOCAL_MACHINE affects the whole computer - all user accounts. As such, it requires administrative permission to set keys in it. If you are running windows Vista or 7, you will need to right-click, "Run as Administrator". If you are using Windows XP as a standard user, you will need to either use "Run As" or logout and then login as an Administrator.

HKEY_CURRENT_USER is specific only to the current user. As such, it can be expected that except in a few unusual circumstances, the program will have permission to create and modify keys within it.

There is a way to make your program request extra permissions when it runs (the UAC prompt), though I do not know of how to implement it. Perhaps there is a thread here about it.

If any mod or such is reading this, would you please edit the snippet at the top with my revised snippet in my post above this? Thanks.

Why not just make an icon for the program and put the in the STARTUP folder of the program list?

This way you won't destroy your registry file if you get the code wrong.

For me personally, there are a number of reasons why using the registry is preferable.

one of them is that the registry location is consistent. In order to use the startup folder properly, you must read it's location out of the registry anyways. (Or mess with system/environment variables or use a windows api call.) The location of the startup folder is easily changed, and it may be somewhere on the disk your program doesn't have permission to write to.

Also, it's not that easy to "destroy your registry file". Look at the code. It opens a key, checks if there was an error, and then sets a value. That's it. There is no magic, "oh I messed up 1 character and now my registry is destroyed".

I've written a complete registry editor, in C++. The registry is very useful, something you should learn about rather than shy away from.

I agree -- for experienced users that understand the O/S. I myself edit the registry often. But for new programmers, it's extremely dangerous. If it's so safe, why does every registry hack include a disclaimer... (objection sustained)

Yes, your code checks for errors. 99% of posts on these forums asking for help don't. I would not suggest registry programming except to experts that already utilize safe coding practices.

My 2 cents...