So I had a REALLY annoying issue where my keyboard wouldnt work when I was using the console on vSphere (on both vSphere client and the vSphere web gui) on my Windows 8.1 PC (fine on others).
After some internet searches I found that the below Windows Updates are to blame and uninstalling them fixes the issues:
KB2961072 KB2971850 KB2912280 KB2973201 KB2973351 KB2993651 KB2984972 KB3000061 KB3002885 KB2962409 KB2967917 KB2975719 KB2994897 KB2984006
Good luck.
