The latest Windows 10 update causes some problems affecting BOINC users.
First, it disables OpenCL use, at least for my GT 440. Installing the Nvidia version of the most recent graphics driver enables it again, though.
Second, it installs Skype. The last time I tried installing Skype on my Windows 10 desktop, just having it installed (even it not running) slowed down all other programs by about 50%, so I uninstalled it soon afterwards. I haven't seen anything yet on whether the version this update installs fixes this slowdown problem.
Another problem with less effect on BOINC:
It changed your default browser without your permission. For me, changing it back worked, though.