I have a psr E423. How do i connect it to music creator 6? does it have anything to do with MIDI files?

The PSR E423 has a USB port to connect it to your computer. Yamaha's product page doesn't mention MIDI at all, just that you can transfer files from the PSR to your computer via USB.
But their support page has links for MIDI drivers for the 423:
http://usa.yamaha.com/products/musical-instruments/keyboards/digitalkeyboards/portable_keyboards/psr-e423/?mode=model
Go there and download the correct MIDI driver for your operating system and then see if the Yamaha shows up in your MIDI device list.
If it does, you can then record MIDI from the keyboard and play back MIDI through the keyboard. It will also open up the world of software synthesizers, giving you access to millions of new sounds you can play using the keyboard.

Yeah.... once you connect it and have it's proper drivers installed, you should see it show up in the list of available midi devices for input to a midi track.

thanks!!!