Double check whether all your SSL/TLS options are still enabled under the advanced tab of Internet Options (inetcpl.cpl from search/run box). There was a Windows Update a while back that caused a reset. Otherwise may want to check your security. Not uncommon for false positives to trip with things like new virus definitions or program updates. Sometimes they will lock an executable after it has been patched (sensing a change in the file), so you may need to update or re-add the exceptions for the executable files (the launcher, boot, update, etc. files in the installation folder).

May want to flush your internet cache and stuff too.