Thanks Felix.
This one doesn't run it, but i know how involved those hypocritical anti-spyware programs can be, so if it was running, i'd have turned it off at the first sign of trouble.
Anywho, after some stuffing around, the problem turned out to be a latent task for some kodak photo software. Killing the process got the show on the road like a dose of the clap.
The AV stuff was just the main distractor.
Interestingly, i tried installing from the big kahuna admin account, but the setup.exe itself failed to open, and just queued itself up in teh task manager. Opening the task manager in that account revealed a truly impressive list worthless junk processes. Evidently there's a lot of excess baggage on this machine...
Thanks all for the help.