Thanks for the clarification.
To quote MS
"Security Center...checking the status of several security essentials on your computer, including firewall settings, Windows automatic updating, anti-malware software settings, Internet security settings, and User Account Control settings."
i.e. It is not in itself a Malware/Antivius program or Firewall.
To quote BT
"BT NetProtect Plus, our advanced security software in association with McAfee, helps protect against online viruses, hackers, spyware and identity theft"
It therefore seems to be the case that you only have one set of protection tools as the BT Netprotect and McAfee are one and the same.
I would therefore retract my earlier suggestion and say you do not have too much security, in fact as has been suggested I would add one additional malware application be it Malwarebytes or Superantispyware.
My final comment is that looking at BT.com it seems they charge £3.49 per month subscription to have Netprotect Plus ie an annual cost of about £42.
You can have equally as good cover using totally free products.