There IS a log file of all device connections and disconnections, in %SystemRoot%\inf\setupapi.dev.log . It is semi-readable text. It contains reports for all devices, not just USB.
Open it in Notepad (or Notepad++ or vi or ex or...), scroll to the bottom, and note that the output for each new device is separated from the previous by a couple of blank lines. The most recent will be at the end. There are timestamps.
If the text doesn't tell you what device(s) are trying to connect, then look for lines like this:
dvi: Searching for hardware ID(s):
and search on the web for vendor ID 1532; then, from likely-looking pages, product ID 0021 (the revision code and the rest of the strings don't matter).
n.b.: There are a large number of sites out there that try to provide this information. Many of them offer driver downloads. Do not download any drivers from anywhere except a) Microsoft update or b) the web site of the company that made your device.