May i recommend to try avg free ? It's free as the name suggests and maybe it will perform better for you. It's a good alternative.
Now, i haven't read the other threads that Earnhardt hinted at, but:
If you only buy something this year make sure it is a good anti-virus/ firewall software. I mean, it's at least your protection man. Be serious about this matter. We all have our favourite programs and it sucks when we have to change something we are used to but sometimes it's necessary.
I sure am not the most experienced user around, but it would be wise to take crackdown21's advice.
Try it and post your results.
Thanks for reading.
gigabyte X58A-UD3R rev.2, core i7 975 3.9ghz (stock voltage), windows 8.1 64-bit, corsair 12gb DDR3 1600mhz 7-7-7-20 RAM, xfx HD 5970 + gigabyte HD 5970 (950mhz/ 1100mhz), coolermaster ultimate 900w PSU.
amd catalyst 14.12 Omega Driver