Internet Security blocking Chrome cast

John, Also have a look @ this link (https://support.avg.com/answers?s=Chromecast#!/feedtype=SINGLE_QUESTION_DETAIL&dc=Windows&criteria=ALLQUESTIONS&id=906b00000004fTJAAY).
AVG Guru

Thanks guys have been busy at work but will try this today and let you know how I get on

Hi
    I am using the free trial version of AVG internet security. I have been impressed and I am going to buy this product if I can solve this issue as its not much good to me if it blocks my cast.
When I use the sofware and try to connect to Chromecast it displays Chromecast not found. If I disable the software Chromecast works ok.
I assume it is to do with the firewall however dont want to play with the settings unless I know what to do for obvious reasons.
​Below is the firewall log for this event.
Any assistance would be appeciated.

"31/01/2015, 18:53:45";"C:\WINDOWS\SYSTEM32\SVCHOST.EXE";"Block";"NETWORK SERVICE";"1448";"Out";"UDP";"5355";"49481";"ff02::1:3";"fe80::7532:2b90:8580:ff73"

Thanks     John

Thanks guys have been busy at work but will try this today and let you know how I get on
https://productforums.google.com/forum/#!topic/chromecast/4VjVMUCurXg This is the only help i was able to find regarding this issue.  The #1 answer is from an offical google employee so it should help. 
I tried the solution that Aaron Fried supplied and indeed he is "the man". I carried out the instructions on the link supplied

https://productforums.google.com/forum/#!topic/chromecast/4VjVMUCurXg

This has fixed the problem for me and I can cast till my hearts content.

Thanks to you also Alan for taking the time to reply.

John C

John, Also have a look @ this link (https://support.avg.com/answers?s=Chromecast#!/feedtype=SINGLE_QUESTION_DETAIL&dc=Windows&criteria=ALLQUESTIONS&id=906b00000004fTJAAY).
AVG Guru