using an XW-P1 thru USB and tried to set up/use midi in Platinum... get an error that says there's not enough memory???  is there a setting or trick using usb midi... i usually just use regular midi.
 
edit... selected MIDIOutSel to MIDI and USBOutSel to MIDI and it saved in midi devices, but won't show any midi input from it.  

First you need to be sure that your keyboard is installed on the computer. It has self loading drivers, but it makes a difference how you connect and run it the first time to be sure these are installed correctly. Check your manual. Then open device manager in Windows and check the status of the device. If it is shown as working in device manager, it should be showing as "Casio USB-MIDI" in Sonar according to your documentation.

It was showing the proper items in device mgr and in devices... and in Sonar and other DAWs.
I loaded the 64 bit drivers from the CASIO site and it is functioning now. 
 
I don't know if the OS upgrade wiped out the old driver or what.  It may have been a brain fart from upgrading my system 3 years back from 32 to 64 bit and never loading the new drivers, since I normally don't use the XW with my desktop computer.