Error trying to update my virus definitions

Hello Marion,
I understand the inconvenience caused, let's work together to fix this issue. Please share a screenshot of the error message to assist you further. You can post the screenshot here on your topic. Click on 'Answer' & then click on the 'Image' [mountain symbol] & follow the instructions.
Best regards,
Alok.

When I try to update my virus definitions and program I get an error message.  Invalid file signature. setup will terminate.  Whats going on?  
error

Hello Marion,
I understand the inconvenience caused, let's work together to fix this issue. Please share a screenshot of the error message to assist you further. You can post the screenshot here on your topic. Click on 'Answer' & then click on the 'Image' [mountain symbol] & follow the instructions.
Best regards,
Alok.