I was a fan of avast, but I thought it felt too sluggish. Antivir is way faster.

Don't buy a firewall or antivirus, ever. It's a waste of money. The free alternatives are just as good.

Stay far, far away from Norton.

Caution and a firewall are enough to protect you from the vast majority of threats. It's been years since I last saw a virus/worm/exploit that didn't rely at least partially on social engineering.

Antivirus is always helpful. Avoid anything that tries to replace the Windows Firewall (like Norton Internet Security). They all seem to really fuck up your system, in my experience, and there's no reason to replace a perfectly good software firewall anyway. If you're using commercial AV, make sure you've got a subscription or it's a waste. A lot of people swear by AVG or clamwin; I'm a fan of avast.

If you want extra tinfoil for your hat, you can make use of virtual machines (http://www.virtualbox.org/) or sandboxes (http://www.sandboxie.com/) to isolate activities from the main system. There's also RVS (http://www.returnilvirtualsystem.com/) and Windows SteadyState (http://www.microsoft.com/windows/products/winfamily/sharedaccess/default.mspx) if you're just looking for a way to quickly restore your system if/when you believe it to be compromised.

Rather than be overly paranoid about security, I usually just make sure I can wipe my computer clean at any time with no risk of losing data. If I suspect something is wrong, I do a new install rather than screwing around trying to diagnose the issue. It's far more practical at work, but it's still not too bad at home.

I'm feeling pretty good about it.

I changed to Avast a while ago, and now I've changed to Avira.

Avast ye lubbers! The dread pirate fluffy is "salvaging" your booty.

avast ye swabs! http://thepiratebay.org/

My own experiences with AVG were underwhelming. I also used Clam for a while, and though clamav/clamd works nicely on *nix, I found clamwin to be fairly lacking. I recommend Avast for free antivirus these days. Just make sure to change or disable the definition update sound, lest you be scared out of your chair on a daily basis.

Something else to keep in mind is that every Firefox addon is a potential attack vector. Limit yourself to the few you actually need. I use only Flashblock and SearchWords.

arrrr I be working on it matey!

In reply to your comment:
“ Avast me mateys! Deputy the Scurvy Dog and his crew have shot across the bow. They suppose the top spot is theirs by right (the bilge rats). Aye, but it's time to hang 'em out to dry on the yardarm. C'mon me hearties and fight like the Rock 'n' Roll pirates ye be! 500 posts is just across the bay and the top spot, by God, can be had if the ship bands together, posts and votes. Summers are made for sailin' the fair seas and pillagin' and most of all ROCK AND ROLL! So, hoist the Jolly Roger and sail with the tide.

Ahoy, Mates!
Zifnab! Swampgirl! Michie! Koshmar! Arrendek! Winkler! Sometimes! Grspec! Choggie! Lisacat! Raven! Sbchapm! Firefly! Bizinichi! Calvados! Farhad! Bicyclerepairman! Deano! Spiff! Intangiblemeg! Dotdude! Krupo! Redthing! Benjee! Deathcow! Woland! Eric3579! Thedeusmachine! Lurgee! Maudlin! Eden! Vidimeister! Gwaan! James Roe! Fletch! Pigeon! Ladybug! Youdiejoe! Gorgonheap! Rembar! Lunkwill! Wumpus! NordlichReiter! Constitutional_Patriot! Looris! NickyP! Lucky760! Wildmanbill! SilentPoet! Megaweapon! Waxwing_slain! Bamdrew! JAPR! Doremifa! Omnithrope! Superganja23! Fedquip! Anea! Lucasgreen! Marinara! Fastfret79! Dog! Coupland! Oohahh! Pyrex! Pho3n1x! Swinginpagan! Joedirt! Dag! Plastiquemonkey!

Sail ye sea beasts! Sail! Hail to Cap'n MLX and bow to none! ARRRRR! ”

Um. What are we doing again?

In reply to your comment:
“ Avast me mateys! Deputy the Scurvy Dog and his crew have shot across the bow. They suppose the top spot is theirs by right (the bilge rats). Aye, but it's time to hang 'em out to dry on the yardarm. C'mon me hearties and fight like the Rock 'n' Roll pirates ye be! 500 posts is just across the bay and the top spot, by God, can be had if the ship bands together, posts and votes. Summers are made for sailin' the fair seas and pillagin' and most of all ROCK AND ROLL! So, hoist the Jolly Roger and sail with the tide.

Ahoy, Mates!
Zifnab! Swampgirl! Michie! Koshmar! Arrendek! Winkler! Sometimes! Grspec! Choggie! Lisacat! Raven! Sbchapm! Firefly! Bizinichi! Calvados! Farhad! Bicyclerepairman! Deano! Spiff! Intangiblemeg! Dotdude! Krupo! Redthing! Benjee! Deathcow! Woland! Eric3579! Thedeusmachine! Lurgee! Maudlin! Eden! Vidimeister! Gwaan! James Roe! Fletch! Pigeon! Ladybug! Youdiejoe! Gorgonheap! Rembar! Lunkwill! Wumpus! NordlichReiter! Constitutional_Patriot! Looris! NickyP! Lucky760! Wildmanbill! SilentPoet! Megaweapon! Waxwing_slain! Bamdrew! JAPR! Doremifa! Omnithrope! Superganja23! Fedquip! Anea! Lucasgreen! Marinara! Fastfret79! Dog! Coupland! Oohahh! Pyrex! Pho3n1x! Swinginpagan! Joedirt! Dag! Plastiquemonkey!

Sail ye sea beasts! Sail! Hail to Cap'n MLX and bow to none! ARRRRR! ”

I'm with ya mate and will post accordingly... AAARRR! I tried this morning, but the Joni Mitchell sift I found didn't suit, the wench is WAY too folk-y. Will commence with the r'n'r smartly!
In reply to your comment:
“ Avast me mateys! Deputy the Scurvy Dog and his crew have shot across the bow. They suppose the top spot is theirs by right (the bilge rats). Aye, but it's time to hang 'em out to dry on the yardarm. C'mon me hearties and fight like the Rock 'n' Roll pirates ye be! 500 posts is just across the bay and the top spot, by God, can be had if the ship bands together, posts and votes. Summers are made for sailin' the fair seas and pillagin' and most of all ROCK AND ROLL! So, hoist the Jolly Roger and sail with the tide.

Ahoy, Mates!
Zifnab! Swampgirl! Michie! Koshmar! Arrendek! Winkler! Sometimes! Grspec! Choggie! Lisacat! Raven! Sbchapm! Firefly! Bizinichi! Calvados! Farhad! Bicyclerepairman! Deano! Spiff! Intangiblemeg! Dotdude! Krupo! Redthing! Benjee! Deathcow! Woland! Eric3579! Thedeusmachine! Lurgee! Maudlin! Eden! Vidimeister! Gwaan! James Roe! Fletch! Pigeon! Ladybug! Youdiejoe! Gorgonheap! Rembar! Lunkwill! Wumpus! NordlichReiter! Constitutional_Patriot! Looris! NickyP! Lucky760! Wildmanbill! SilentPoet! Megaweapon! Waxwing_slain! Bamdrew! JAPR! Doremifa! Omnithrope! Superganja23! Fedquip! Anea! Lucasgreen! Marinara! Fastfret79! Dog! Coupland! Oohahh! Pyrex! Pho3n1x! Swinginpagan! Joedirt! Dag! Plastiquemonkey!

Sail ye sea beasts! Sail! Hail to Cap'n MLX and bow to none! ARRRRR! ”

Avast me mateys! Deputy the Scurvy Dog and his crew have shot across the bow. They suppose the top spot is theirs by right (the bilge rats). Aye, but it's time to hang 'em out to dry on the yardarm. C'mon me hearties and fight like the Rock 'n' Roll pirates ye be! 500 posts is just across the bay and the top spot, by God, can be had if the ship bands together, posts and votes. Summers are made for sailin' the fair seas and pillagin' and most of all ROCK AND ROLL! So, hoist the Jolly Roger and sail with the tide.

Ahoy, Mates!
Zifnab! Swampgirl! Michie! Koshmar! Arrendek! Winkler! Sometimes! Grspec! Choggie! Lisacat! Raven! Sbchapm! Firefly! Bizinichi! Calvados! Farhad! Bicyclerepairman! Deano! Spiff! Intangiblemeg! Dotdude! Krupo! Redthing! Benjee! Deathcow! Woland! Eric3579! Thedeusmachine! Lurgee! Maudlin! Eden! Vidimeister! Gwaan! James Roe! Fletch! Pigeon! Ladybug! Youdiejoe! Gorgonheap! Rembar! Lunkwill! Wumpus! NordlichReiter! Constitutional_Patriot! Looris! NickyP! Lucky760! Wildmanbill! SilentPoet! Megaweapon! Waxwing_slain! Bamdrew! JAPR! Doremifa! Omnithrope! Superganja23! Fedquip! Anea! Lucasgreen! Marinara! Fastfret79! Dog! Coupland! Oohahh! Pyrex! Pho3n1x! Swinginpagan! Joedirt! Dag! Plastiquemonkey!

Sail ye sea beasts! Sail! Hail to Cap'n MLX and bow to none! ARRRRR!

Avast me mateys! Deputy the Scurvy Dog and his crew have shot across the bow. They suppose the top spot is theirs by right (the bilge rats). Aye, but it's time to hang 'em out to dry on the yardarm. C'mon me hearties and fight like the Rock 'n' Roll pirates ye be! 500 posts is just across the bay and the top spot, by God, can be had if the ship bands together, posts and votes. Summers are made for sailin' the fair seas and pillagin' and most of all ROCK AND ROLL! So, hoist the Jolly Roger and sail with the tide.

Ahoy, Mates!
Zifnab! Swampgirl! Michie! Koshmar! Arrendek! Winkler! Sometimes! Grspec! Choggie! Lisacat! Raven! Sbchapm! Firefly! Bizinichi! Calvados! Farhad! Bicyclerepairman! Deano! Spiff! Intangiblemeg! Dotdude! Krupo! Redthing! Benjee! Deathcow! Woland! Eric3579! Thedeusmachine! Lurgee! Maudlin! Eden! Vidimeister! Gwaan! James Roe! Fletch! Pigeon! Ladybug! Youdiejoe! Gorgonheap! Rembar! Lunkwill! Wumpus! NordlichReiter! Constitutional_Patriot! Looris! NickyP! Lucky760! Wildmanbill! SilentPoet! Megaweapon! Waxwing_slain! Bamdrew! JAPR! Doremifa! Omnithrope! Superganja23! Fedquip! Anea! Lucasgreen! Marinara! Fastfret79! Dog! Coupland! Oohahh! Pyrex! Pho3n1x! Swinginpagan! Joedirt! Dag! Plastiquemonkey!

Sail ye sea beasts! Sail! Hail to Cap'n MLX and bow to none! ARRRRR!

Avast me mateys! Deputy the Scurvy Dog and his crew have shot across the bow. They suppose the top spot is theirs by right (the bilge rats). Aye, but it's time to hang 'em out to dry on the yardarm. C'mon me hearties and fight like the Rock 'n' Roll pirates ye be! 500 posts is just across the bay and the top spot, by God, can be had if the ship bands together, posts and votes. Summers are made for sailin' the fair seas and pillagin' and most of all ROCK AND ROLL! So, hoist the Jolly Roger and sail with the tide.

Ahoy, Mates!
Zifnab! Swampgirl! Michie! Koshmar! Arrendek! Winkler! Sometimes! Grspec! Choggie! Lisacat! Raven! Sbchapm! Firefly! Bizinichi! Calvados! Farhad! Bicyclerepairman! Deano! Spiff! Intangiblemeg! Dotdude! Krupo! Redthing! Benjee! Deathcow! Woland! Eric3579! Thedeusmachine! Lurgee! Maudlin! Eden! Vidimeister! Gwaan! James Roe! Fletch! Pigeon! Ladybug! Youdiejoe! Gorgonheap! Rembar! Lunkwill! Wumpus! NordlichReiter! Constitutional_Patriot! Looris! NickyP! Lucky760! Wildmanbill! SilentPoet! Megaweapon! Waxwing_slain! Bamdrew! JAPR! Doremifa! Omnithrope! Superganja23! Fedquip! Anea! Lucasgreen! Marinara! Fastfret79! Dog! Coupland! Oohahh! Pyrex! Pho3n1x! Swinginpagan! Joedirt! Dag! Plastiquemonkey!

Sail ye sea beasts! Sail! Hail to Cap'n MLX and bow to none! ARRRRR!

Avast me mateys! Deputy the Scurvy Dog and his crew have shot across the bow. They suppose the top spot is theirs by right (the bilge rats). Aye, but it's time to hang 'em out to dry on the yardarm. C'mon me hearties and fight like the Rock 'n' Roll pirates ye be! 500 posts is just across the bay and the top spot, by God, can be had if the ship bands together, posts and votes. Summers are made for sailin' the fair seas and pillagin' and most of all ROCK AND ROLL! So, hoist the Jolly Roger and sail with the tide.

Ahoy, Mates!
Zifnab! Swampgirl! Michie! Koshmar! Arrendek! Winkler! Sometimes! Grspec! Choggie! Lisacat! Raven! Sbchapm! Firefly! Bizinichi! Calvados! Farhad! Bicyclerepairman! Deano! Spiff! Intangiblemeg! Dotdude! Krupo! Redthing! Benjee! Deathcow! Woland! Eric3579! Thedeusmachine! Lurgee! Maudlin! Eden! Vidimeister! Gwaan! James Roe! Fletch! Pigeon! Ladybug! Youdiejoe! Gorgonheap! Rembar! Lunkwill! Wumpus! NordlichReiter! Constitutional_Patriot! Looris! NickyP! Lucky760! Wildmanbill! SilentPoet! Megaweapon! Waxwing_slain! Bamdrew! JAPR! Doremifa! Omnithrope! Superganja23! Fedquip! Anea! Lucasgreen! Marinara! Fastfret79! Dog! Coupland! Oohahh! Pyrex! Pho3n1x! Swinginpagan! Joedirt! Dag! Plastiquemonkey!

Sail ye sea beasts! Sail! Hail to Cap'n MLX and bow to none! ARRRRR!

Avast me mateys! Deputy the Scurvy Dog and his crew have shot across the bow. They suppose the top spot is theirs by right (the bilge rats). Aye, but it's time to hang 'em out to dry on the yardarm. C'mon me hearties and fight like the Rock 'n' Roll pirates ye be! 500 posts is just across the bay and the top spot, by God, can be had if the ship bands together, posts and votes. Summers are made for sailin' the fair seas and pillagin' and most of all ROCK AND ROLL! So, hoist the Jolly Roger and sail with the tide.

Ahoy, Mates!
Zifnab! Swampgirl! Michie! Koshmar! Arrendek! Winkler! Sometimes! Grspec! Choggie! Lisacat! Raven! Sbchapm! Firefly! Bizinichi! Calvados! Farhad! Bicyclerepairman! Deano! Spiff! Intangiblemeg! Dotdude! Krupo! Redthing! Benjee! Deathcow! Woland! Eric3579! Thedeusmachine! Lurgee! Maudlin! Eden! Vidimeister! Gwaan! James Roe! Fletch! Pigeon! Ladybug! Youdiejoe! Gorgonheap! Rembar! Lunkwill! Wumpus! NordlichReiter! Constitutional_Patriot! Looris! NickyP! Lucky760! Wildmanbill! SilentPoet! Megaweapon! Waxwing_slain! Bamdrew! JAPR! Doremifa! Omnithrope! Superganja23! Fedquip! Anea! Lucasgreen! Marinara! Fastfret79! Dog! Coupland! Oohahh! Pyrex! Pho3n1x! Swinginpagan! Joedirt! Dag! Plastiquemonkey!

Sail ye sea beasts! Sail! Hail to Cap'n MLX and bow to none! ARRRRR!

Avast me mateys! Deputy the Scurvy Dog and his crew have shot across the bow. They suppose the top spot is theirs by right (the bilge rats). Aye, but it's time to hang 'em out to dry on the yardarm. C'mon me hearties and fight like the Rock 'n' Roll pirates ye be! 500 posts is just across the bay and the top spot, by God, can be had if the ship bands together, posts and votes. Summers are made for sailin' the fair seas and pillagin' and most of all ROCK AND ROLL! So, hoist the Jolly Roger and sail with the tide.

Ahoy, Mates!
Zifnab! Swampgirl! Michie! Koshmar! Arrendek! Winkler! Sometimes! Grspec! Choggie! Lisacat! Raven! Sbchapm! Firefly! Bizinichi! Calvados! Farhad! Bicyclerepairman! Deano! Spiff! Intangiblemeg! Dotdude! Krupo! Redthing! Benjee! Deathcow! Woland! Eric3579! Thedeusmachine! Lurgee! Maudlin! Eden! Vidimeister! Gwaan! James Roe! Fletch! Pigeon! Ladybug! Youdiejoe! Gorgonheap! Rembar! Lunkwill! Wumpus! NordlichReiter! Constitutional_Patriot! Looris! NickyP! Lucky760! Wildmanbill! SilentPoet! Megaweapon! Waxwing_slain! Bamdrew! JAPR! Doremifa! Omnithrope! Superganja23! Fedquip! Anea! Lucasgreen! Marinara! Fastfret79! Dog! Coupland! Oohahh! Pyrex! Pho3n1x! Swinginpagan! Joedirt! Dag! Plastiquemonkey!

Sail ye sea beasts! Sail! Hail to Cap'n MLX and bow to none! ARRRRR!