Is Panda AV your realtime protection? or are you using Windows 8.1 built in protection,such as Defender,smartscreen,UAC & Windows firewall
I am assuming you are using Malwarebytes Antimalware for on demand scanning ?
I would consider Using UAC,Panda AV & Windows firewall for your realtime protection
Malwarebytes Antimalware for on demand scanning
CCleaner or Privazer if not already installed
Consider uBlock in place of ABD + and HTTPS Everywhere in Chrome & FF