I've just switched over to a new computer, and the proprietary anti-virus/firewall software I've used in the past from my ISP service could be a major pain to get onto the new computer.

I was wondering if anyone had suggestions for what to use instead?

Microsoft Security Essentials.

MSE or gtfo.

Avast! if you want real-time protection. MSE doesn't have that, but it's a good scanner.

Free:

Avast! -- a full-featured free antivirus program. The Web Shield and Script shield are really what make it shine with their real-time protection often only found in the better paid AVs.

MSE -- for those who want just the very basic of protection.

Paid:

NOD32 -- Extremely light and very effective. Has proven itself a worthy program time and time again for those who want the best

VIPRE -- very generous pricing model and has received many accolades from people whose opinion I hold highly.

Kaspersky used to go on here, but with 2012 I just really don't like where they are going, constantly removing options and choices.