Delmaryoder - I think that the suggestion that you can re-use your still-current AVG code is valid - if so, you've paid for it, so run it out while you can.
Once it does expire, the hint about the free Avast is a good one. It certainly doesn't cost anything to try. And Avast will uninstall from your system without leaving annoying 'riders', if you don't like it.
I'm a 10+ years Linux user, but as an ex Windows tech I keep my hand in by helping with several friends / families Windows installs - mostly XP, as Vista isn't attractive to them, but Win-7 is gaining ground, being rather more hardware and user friendly.
On their setups we go around the Windows firewall and use the free version of Zone-Alarm, but I see that as just a part-way measure, and all are also behind a firewalled router - using the low-cost ASUS versions, though other good brands would do as well.
However, nothing is perfect - and the kids do tend to click on nasties at times, so a good AV program - set up properly, and then USED - is essential. Avast covers all the bases, has frequent updates (can be auto or manual, if you don't want to allow anything 'auto' Internet access), and has several selectable levels of Scan - or the "all of everything" mode can be used. There's also the while on Internet guard - has a rotating icon in the system tray to show it's working.
You install Avast, and then register for a free key, which is valid and re-usable on re-installs for 14-months, and is renewable.
There are those - probably less experienced - Linux users who like to boast that Linux is "totally invulnerable" on the Internet... I'm in Sydney, Oz - and have a nice Harbour Bridge to sell those folk, for a mere $-Million or two...
While the Windows Trojans and Viruses don't run in Linux/Unix systems - Worms and Rootkits certainly do, and while those are usually aimed at Servers - there's no telling what the Evil Ones on the Dark Side might do - so my Linux system runs the Shorewall firewall, and - is behind a firewalled router. Not one problem in 10+ years - but there's no telling what the Dark Side might do next!
And although Linux isn't affected by the Windows Trojans and Viruses - Windows using friends can be... That is - while my user-logon or another on this PC (user logons are fully separated in Linux, they aren't user-profiles) - can have dozens+ Windows Trojans and Viruses in it, not affecting it - they can infest "any" material transferred from it to a Windows system - an email attachment (not very likely) - or text files, images, graphics, videos, etc - transferred on CDs, DVDs, USB-drives, etc.
There are AV applications for Linux - Clamav and others - but not all Linux users run one, and check material intended for their Windows-using friends. I do - since the time in 2003 when I was caught-out badly - and transferred a severe infestation via some videos on a CD to a friend's XP-Pro install. And I hadn't told him to run his AV over the material before running it. My fault entirely - and I ended up spending several hours copying-off (and checking before re-using) his essential data - a full re-install of XP - and all of his programs...
So when Windows folk get material from a Linux user - isolate and AV check it before using it.
Linux users can place all material intended for transfer to Windows in a single temporary directory, and deep-scan that with currently updated Clamav. Clean material can then be copied from that directory into K3b-etc to write to CD/DVD or copy to USB-drive. USB-drives, after clearing of previous data, can also be scanned with Clamav.
But still advise your Windows recipients to check the material with their currently updated AV program, too.
(Note that, if a Windows system is so badly infested-etc that it can't boot, all needed data from the system can be recovered using a Linux LiveCD/DVD. That runs a Linux system in RAM without starting Windows, without further damaging the Windows install. That can copy data to CD, DVD, USB-drive, or external Hard-Drive. BUT - that data MUST be properly checked before being used in the Windows re-install...!)