Unity Web player impossible download

Hello all , i have problem , i wanted to play another game on firefox , but they say i don't have the last version of unity web player . Then i try to download the last version but download stuck half of the bar i don't understand why ...
Then i tried to uninstall first , but it's not possible too )= they say on control pannel : ''
Please wait for the modification of a program '' ...then a lot of people recommend revo uninstaller to uninstall unity web player , but uninstall doesn't work too ( stuck half bar ) .
I can do nothing please help me to fix this )=

 

have you tried "run as administrator"

 

yes i already trie to run as administrator but that change nothing )=

 

up !

 

up !