I have updated Defender till Definition Update 1.14.1361.6 for BETA Windows Defender (KB915597) during Microsoft update, or at least I guessed it !!! However product remains with the first original signature, inspite of many updates. Icon at taks bar indicates a exclamation point and remains like that after installation. Everytime I go to Windows Update, Defender is there again and again, saying I have downloaded it and needs to be installed. Useless try to install. Does not work. Where is the update file ? Does it happen with anyone ? How can I solve it, please??