seriously, use linux for browsing and a seperate windows development pc that has no permanent internet connection.

and spend more hours switching between than it would take to get the cash to pay for a subscription...

even the best antivirus, software firewall, spam filter, bla, can't protect you 100%.

true but being careful, using free stuff, and not being afraid to reformat every once and a while can be.

Nor can Linux...
If you don't know how to secure your Linux, I would recommend using Windows and some AV-Software of your choice. Use the internal Windows Firewall, it is enough protection.
I can't understand those geeks who try to "proselytize" everbody to use Linux. Linux is NOT the best OS in the world. It might be the best for some kind of tasks, but it is definitely no panacea!

Maybe try this Programm... its free and powerfull (my opinion)

http://www.emsisoft.com/en/software/free/

Here's what I'm running, and I've had no problems. You have to pay for Spysweeper and it's fast approaching 300,000 on the protection list:

Virus: AntiVir
Spy/Adware: Webroot Spysweeper
Firewall: Zonealarm

avg does the job.

I too have AVG7.5 but from now on you need to buy and upgrade to AVG 8.0 and so
its not free anymore,unless you stick to AVG7.5(which will not get the updated virus defs)
Kapersky again is not free.
A-squared is again only free for 30 days.
I am gonna give Avast 4.7 a try coz it appears free for home use atleast.
Otherwise its going to be Antivir + Zonealarm + some anti spyware

and yeah Vista has its own firewall,which should be good enough I guess
and it has WindowsDefender which is antispyware(unless it is itself a spy :-))