If you have a problem updating the Unity player, follow the instructions below:
Usually the folder AppData is hidden in the Windows system. Please use the google search to find out how to display hidden files and folders in your version of Windows.
When you do this, find the folder AppData and it contains the folders Unity. Delete folders Unity.
Unity folders needs to be deleted in three directories:
C: \ user \your username in Windows \ AppData \ Local
C: \ user \your username in Windows \ AppData \ LocalLow
C: \ user \ your username in Windows \ AppData \ Roaming
then restart your system
then install the unity player
and then restart the system again
N.B. All browsers must be closed during installation