The thing is installation was successful but I can't activate my product. It syas that internet connection is needed but it's perfectly fine. (i.e. I'm posting this onto this website now), so I'm not sure what to do. Please help. Thanks so much.
Please try the below steps before activation ;
Check in control panel – Add/Remove programs and uninstall any other security software that might be installed
Then clear the temporary files and cookies on your Internet explorer.
Run the Mcpreinstall tool from here http://service.mcafee.com/faqdocument.aspx?id=TS100614
Right click on M icon and click on product setup .
Follow the onscreen prompts to activate your subscription