What does optout.doubleclick.net do? DOes that prevent your computer from storing cookies? Does it prevent trojan horses from entering your p.c. If not, how do you prevent a trojan horse from entering your p.c. Is there something in windows xp that can prevent them?:confused: AND, if I leave a trojan horse in my avg free virus vault will it then not effect my computer at all? Earlier LTheobald said that you should leave it in the vault, will it then eventually go away? I know that's a lot of questions, but I don't need another virus on my PC at home, I use it for work purposes and am pretty PC illiterate and wouldn't know what to do if my PC went down :o)

Its time you did some cleaning on your machine then.
To make sure everything is running fine run some anti spyware apps (make sure that they are updated first ;)) (A couple of good removal tools are Spybot (http://www.safer-networking.org/) and Adaware (http://www.lavasoftusa.com/software/adaware/)). Delete EVERYTHING they find.

ALso an on line virus and spyware scanner is Trend Housecall (http://housecall.trendmicro.com/) I would recommend to delete everything it finds.
Spybot has a great feature called Teatimer. This monitors your system and helps to stop things like this getting hold in the first place.
Both the spyware apps need to be run in both normal and safe modes to ensure everything bad is removed.

Another handy app to use is CCleaner (http://www.ccleaner.com), this helps to remove excess junk from your system and keeps things running better.

What does optout.doubleclick.net do? - Spyware
DOes that prevent your computer from storing cookies? - Nope
Does it prevent trojan horses from entering your p.c. - Nope
If not, how do you prevent a trojan horse from entering your p.c. - See above
Is there something in windows xp that can prevent them? - Ditto
AND, if I leave a trojan horse in my avg free virus vault will it then not effect my computer at all? - The Vault is a safe area that windows doesn't access
Earlier LTheobald said that you should leave it in the vault, will it then eventually go away? - Yep, but I would delete anything like this when its first detected

SO AVG free is not enough protection? What does spybot and adaware do that avg free doesn't? How do you erase a trojan horse that's in the virus vault... Ltheobald was saying that if you just click delete it could delete other necessary programs? DO I just right click on the highlighted trojan horse and then click delete if this IS OK?

SO AVG free is not enough protection? - It never hurts to scan with another anti virus scanner and as Trend is online it's always up to date
What does spybot and adaware do that avg free doesn't? - Removes spyware. Basically small programs that monitor what you do online and give lots of popup adverts
How do you erase a trojan horse that's in the virus vault... Ltheobald was saying that if you just click delete it could delete other necessary programs?
DO I just right click on the highlighted trojan horse and then click delete if this IS OK? - Worth a try. AVG may have an "empty vault" command. Sorry I can't help more, but I don't use AVG. Also I always set my anti virus apps to delete on detection

Thanks, I will try the things that you suggested! I appreciate it :) :) :)

Anti-virus and anti-spyware utilities are different. They each guard against different menaces so both need to be used. Spyware and Viruses are different things.

Doubleclick is a company that sells targeted advertising. You will frequently see doubleclick when you hover over links and hotspots on a web page.

Is Trojan horse a type of spyware or is it a virus? It says in the risk category on my virus vault that it is low risk. I guess if it is in the virus vault then it probably is a virus... cgirl<duh!:o

A Trojan Horse can be one or the other. A Trojan Horse is a piece of code hidden within another program that does something different then the intended program. Generally Trojan Horses are not viruses because they don't meet one characteristic of a virus which is that it self replicates.

Thanks... I will make sure I download some spyware!

Thanks...I will make sure I download some spyware!

I hope you mean Anti Spyware ;)

Oh! Yea! Hehe I meant to say spybot... oops!