usb driver not working in quartus 12.0

A couple of points that might be helpful to the reader of your post (for future reference):

1. what version of Blaster? Whose version of the USB drivers?

2. what OS?

The answer you might get could be affected by these pieces of information.

Anyway, what I've observed about Blaster II (in my case, the Chinese-made ones with the Altera name on them): when we initially started using them, we had problems with the USB driver files, device not recognized, etc. I believe we went out onto the Internet and found another set of driver files and these worked. I don't have a URL from where we got these other driver files, but we simply did a Google search to find them. The point is that we had to resort to other means to get a working set of USB drivers.

We're running Blaster II with 3 different versions of Quartus II (v11, v12, full and web versions) on Windows laptops running both XP and Windows 7.

Hope this helps.

cheers,

jim