Do
not install the driver from the disk, as the PSR-I425 is an older model and the USB-MIDI driver on the enclosed CD is surely old. Instead, go to the following page:
http://download.yamaha.com/search/p...ry_id2=16084&category_id3=&product_id=1686058
(I know it says "PSR-I455," but that's okay.)
You want to download whichever version of the two "USB-MIDI Driver V3.1.4 for Win" files applies to your computer-- i.e., the 64-bit version or the 32-bit version. If you aren't sure whether you have a 32-bit or 64-bit computer and version of Windows, check its "System" properties to see, so you don't download the wrong driver version.
Before you install the driver,
make sure your PSR-I425 is connected to your computer via USB and is turned on. Then you can install the driver. Once the installation is finished, your PSR-I425 should show up in Ableton Live 9 and Mixcraft-- I'm guessing that it will be listed as "Yamaha PortaTone," but I'm not sure.
