A lot of "expert" advice from those who obviously know little about Windows.
To suggest checking PSU, memory or "shoddy drivers" is laughable.
In case some are slow readers, let me recap: Freezing issues after installing 8.1.
All my video drivers are up to date, may sata drivers up to date, ect.....never had a Win 8 crash period, until the day after installing the official Win8.1 upgrade.
In my case the freezes are about once a week and occur when playing video, be on up-to-date media Player, up-to-date VLC, or on YouTube (with up-to-date shockwave).
This is a WINDOWS BUG. A known, and growing WINDOWS BUG. Don't blame it on AMD , Nvidia or Flash.....these crashes did not start after installing THEIR drivers, it started after installing 8.1.