nios2-download hangs, then "There is a problem with your Quartus II installation"

After some more experiments, I copied from quartus/bin directory all of these files jtag*.dll into the nios2eds/bin directory. This got me past the error, but now I see that nios2-download prints "There are no JTAG cables available on your system." And this is after I've downloaded the .sof file. One step forward, but haven't recovered from the "blow-up" of nios2 a week ago.

Dec 28, update: I've tried to clean out registry of all traces of Altera software, downloaded 7.2sp3 and installed. Now the symptom is that I cannot download a .sof, and the jtag server does not start. I then downloaded stand-alone programmer version 9.1, but this was no help either. The problem is that I can install / uninstall jtagserver with admin console in Vista x32, but I cannot "start" the server, it always stops right away after it is started. I copied a bunch of .dll 's to the windows\system32 directory, but that was no help either. The usb driver is installed, so that's not it. HERE'S MY QUESTION: what is jtag server doing that it does not start? Since there are no printouts, I really don't have any clues. Perhaps one possible is that the command sc query jtagserver, if issued right after boot-up, shows (on the first time) an error code of 1077 (0x435).

Dec 29, update: uninstalled everything, deleted all traces of Altera in registry that I can find. Re-installed from CD version 7.2 (after copying CD to eliminate chance of bad area). Now jtagserver is RUNNING again! That's good, but I'm back to no JTAG cables available message from nios2-download. (I can still download .sof). Still is a real mystery. The AlteraUSBBlaster driver is present, is installed, says the Vista sc utility. The registry entries look good. Why can't nios2-download see anything? The .sof and .elf I am using are the Terasic control panel, which used to work. (.sof still works).