FD in Kernel 2.4.x

Hi! I am newbie in this list! .. I'm Federico Edelman Anaya ... well! .. I have a question ...

I need increase the FD (File Descriptors) ... I was change the value of the FD in kernel 2.2.17:

/usr/include/bits/types.h:
#define __FD_SETSIZE 1024 -> 4096

/usr/src/linux/include/linux/posix_types.h
#define __FD_SETSIZE 1024 -> 4096

/usr/src/linux/include/linux/tasks.h
#define NR_TASKS 512 -> 2048 /* On x86 Max 4092, or
4090 w/APM configured. */

Well... Kernel 2.4.3:
/usr/include/bits/types.h:
#define __FD_SETSIZE 1024 -> 4096

/usr/src/linux/include/linux/posix_types.h
#define __FD_SETSIZE 1024 -> 4096

It's only change was posible to do ... Because, tasks.h doesn't exist!

How can I do to increase the FD in the Kernel 2.4.3?

Thanks!