Honored Contributor
Honored ContributorI was having the same kind of issue, I found a culprit however and fixed it. I actually had reinstalled/changed versions of Quartus and the USB Blaster driver started acting the same way for me. Versions 12.1sp2 and 15.1 on Windows 7 64-bit. Posting this in case anyone comes looking. I think this is because I didn't have one of the .exe installers setup the driver. Pointing Windows at the driver provided in either installation gave me the same issue with detecting the programmer in Quartus.
Essentially, I think the driver script isn't adding usbblstr64.dll into the system32 directory. I looked at it, and it seems like its structured so amd64(x86-64) systems should get it, but it wasn't installed. I copied */quartus/drivers/usb-blaster/x64/usbblstr64.dll into Windows/system32, and when Windows next went to find the driver via a little turning it off and on again, the problem went away. Happened on a similar coworker's setup also. Can anyone else replicate this?
