Thanks for that tip.
Regarding the SiLib.sys driver... I only seem to find the pdf release notes from the Carrona site. A Google search wasn't much help either. And that's just my first driver to update.
That driver appears to be part of Garmin's ANT agent software... installed to work with a Garmin Forerunner 405.
I just reinstalled the Garmin USB drivers after changing the installer properties to run in compatibility mode for XP.sp3. Let's see if that makes a difference.
Edit: I ran the system file checker just to see if it turned up anything... and it found no issues.
Edit 2: I connected the Edge 305 to the computer, got the normal USB connect tones (as I held my breath) and it said it installed the drivers. No BSOD. Maybe that compatibility mode made a difference. I'll keep an eye on it.