Vista + USB + Midi + Yamaha = PITA

I spent many hours wondering why our Yamaha PSR-260 midi-capable keyboard was not recognised  when plugged into our Vista PC via a midi-USB cable. So many hours, in fact, that I returned one USB midi cable as faulty, and only when the second cable didn't work did I look elsewhere for the problem.

To cut a long story short, the Vista generic USB midi cable driver does not appear to work with this type of cable, for Yamaha keyboards at least. 

Note that some of these instructions are from memory, so might be incorrect; but you're an intelligent person - you know what to do.

 With the midi keyboard switched off, you need to do the following [I'm assuming you've plugged the midi plugs into the keyboard; make sure the cable plug marked 'IN' is plugged into the keyboard midi socket marked 'OUT', and vice versa]:

1. Download the appropriate drivers from here, and extract them. There appear to be loads of files, and I have no idea what each of them means
2. In Vista's control panel, choose Add New Hardware, and the Add New Hardware wizard pops up. Click next.
3. Choose "Install the hardware that I manually...(Advanced); Click next
4. Choose "Show all devices"; Click next
5. Click on "Have Disk", and browse to the directory you extracted the drivers to, and choose one of the .inf files there. Click OK.
   
6. The drivers should install.
   
7. That should take you to a list of manufacturers and their components. Scroll down the list of manufacturers to Yamaha Corporation, and choose "Yamaha USB Midi Driver".
8. Select it; Click on next, and follow the rest of the instructions.
9. Reboot.
10. Plug in the midi USB cable. 
11. Hopefully, your keyboard should be recognized. 

If the above doesn't work for you, I'm sorry; it's just nature's way of saying your PC hates you.

Another tool I used, which shows whether midi signals are being received or not, is Midi-ox.

Good luck.