How can I make a similar typing like Windows' textboxes (i mean, when you hold a button in windows, it wait after the first press for a while, and goes faster after..). It doesn't matter if delay is same or not, I just want to get proper text input

Just make sure you TranslateMessage() all incoming messages - this will automatically generate appropriate WM_CHAR messages (including delay, dead characters etc).

The harder thing is to correctly implement inserting/removing/editing.

Can't figure it out.. :( I made a global char, and

...
case WM_DOWN:
g_GlobalChar = wParam;

and used it directly:

char temp[2];
temp[0] = g_GlobalChar;
temp[1] = '\0';

PrintFunction( temp );

Bad thing is, it keeps the previous pressed value after the key is up again. Can you write a short example so I can see how I can do it?