Also having the same Windows Explorer stopping and then restarting issue. It is happening with alarming frequency. To be clear, this is NOT the SU thumbs dumping SU, this is systemic, possibly not even associated with SU. See Griffin's post from Nov. '14.
Win 7, Nvidia Quadro 4200, SU 2015 Pro with maybe 5 or 6 extensions, including Kerkythea and Vray 2.
Hard to diagnose as we as an office made significant network system changes at or near the same time as my SU 2015 Pro install.
Two Windows rebuilds / reloads, eliminating all unused or old software didn't solve the issue, fyi.
Thank you for the advice, all. I will try renaming the thumb .dll and wait and see.