Ick. That's not good at all. I presume this is a host system you've been using for a while with no problems prior to installing the Tech Preview... Was this same host previously running WS 9.0.x?
We'd greatly appreciate if you could provide a copy of the crash dump files, any relevant-looking event log entries from the host, plus a description of the hardware on which you're running Workstation. (Decoding Windows dumps isn't my thing at all, but I know there are others here who will certainly dig into it.) If for whatever reason you don't want to post them here, just PM me and we'll sort it out.
Many thanks,
--
Darius