Ok, so I assume you are on a 64 bit windows then. Well, there's my input.
Windows 7 - 64 bits. OS 2.0.0.1888 in Calculator TI Nspire...
TI Connect is too hard and complicated :S
and AFAIK, ti-connect doesn't work on windows 7.
TI-Connnect actually works on Windows 7. I have it running on it (64 bit patch). It doesn't work 100% of the time, though.
TI-Connect does work on Windows 7 64-bit, I run it myself, however I did run into a possibly similar problem involving drivers.
When installing TI-Connect straight from the disk, then checking for updates, TI-Connect update feature says you have the latest version, 1.6. However, upon further investigation on TI's website, there is actually one newer version (1.6.1) with a single fix-- adding 64-bit support.
I had to reinstall TI-Connect manually from the website to get the update. If you haven't done this, it's probably your problem.
http://education.ti.com/calculators/downloads/US/Software/Detail?id=183