Win32, C and SendMessageTimeout - Request for help

Hi!

For the Windows installer, I have used a small helper program for about
two years in order to update the Windows %PATH% environment variable.
This helper program adds/removes Subversion's binary path (path to
svn.exe) and are using SendMessageTimeout in order to make the Windows
system aware of the change in %PATH% for the NT-variations.

The problem is:
Sometimes, the Windows system is not aware of the change in path and must
be rebooted. This is probably a rare problem, but happends from time to
time on misc. 2k and XP systems.

Why does this problem come up. Is there something I've done wrong (see
below) or is it some kind of Windows problem?

You will find this program in Subersion's repository:
  packages/win32-innosetup/tools/svnpath/main.c

SendMessageTimeout if found in the lines 278 and 614.

----------------------------------------------------------------------
        /* Tell the system about the new path */
        SendMessageTimeout(HWND_BROADCAST, WM_SETTINGCHANGE, 0,
                           (LPARAM) "Environment", SMTO_ABORTIFHUNG,
                            5000, &lRet);
----------------------------------------------------------------------

Any help is welcome.

Thanks in advance.

Jostein

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