I was having the same problem as a lot of you guys, when searching google trying to resolve what was becoming a very regular freezing schedule, I realized when viewing others logs, there was a common program that a lot of us were running. UPS Worldship.
I kept getting MSSQL$UPSWSDBSERVER errors in my event log, and searched based off of this quite a few times. I decided to uninstall UPS Worldship... my freezing completely stopped.
While it is extremely inconvenient to not have this software on my computer, at least it is now stable and I can work on things like spreadsheets without having to worry about losing unsaved data. If you are running this software, try uninstalling it and see if it works for you.
Also, if anybody is able to resolve their issues by doing this and finds a workaround for the ups software, please post back your findings.