Open a new project. Set it up with your preferred I/O settings. Then save the project as a Template:
File/Save As Template. Give it a name.
From now on, open each new project with the new template. All your settings will be as you originally set them.
Cubase 7.5.30, Halion 5.04, Wavelab 8.5
Intel Core i7, 16 Gb RAM, ASUS Z97-A mobo, 256 Gb SATA SSD system drive, 2TB SATA media drive, 500 Gb storage drive
UAD-2 Solo, UAD-2 Duo, Yamaha KX8, Steinberg MR816csx, CC121, Waves 9: IR-1, Vocal and Diamond Bundles, L316, iZotope Ozone 5, RX2