My Miditech keyboard is correctly installed in Windows XP, but I cannot see the driver as a MIDI input in my DAW software. What is the problem?

This is a typical Windows XP fault, when you have a Logitech or Labtec device installed in your system, such as a Webcam etc. The Logitech drivers do not work with the Windows XP class compliant installation, and prevents, that you can see the class compliant driver in your music software.
Normally it works, to de-install the Logitech device, then re-install the MIDI keyboard again on a different USB port, and it will work. After this you can re-install your Logitech device, and both devices will work.