For us to check your computer's specifications, can you please provide the exact model name of your laptop. Also just to verify, you said the computer updated to Windows 8.1, were you able to follow the steps in properly upgrading to Windows 8.1 posted here?
To the other topic: I think I did it basicly according to the instructions. I didn't create Backup disks which I don't see relevant to this issue. Also I performed the vaio update process before installing win8.1 I think all updates were installed, but to be honest, I can't tell you anymore whether 100% of them were installed before the 8.1 installation, but I think they were.
Once the 8.1 upgrade procedure started, I had no possibilities to influence it, until it was fully completed.
Immediately after the update, the videos in the metro apps didn't work anymore. Installations of all available updates on the sony website, from Microsoft and the other 3rd parties (NVidia/Intel) were successfully performed but didn't help either.
After going to 8.1 I was getting distorted vids at various screen sizes, and went into Vaio Control Center and under image quality turned OFF both selections for "x-reality for mobile" and that cured it. Maybe just me though.