How can i get rid of a virus if have it already in my computer

How can I get rid of a virus that I have already in my computer

Know thine enemy... lol. Find out what virus it is, then a cure can be found, unless you feel like reformatting. Report back here with the name of the virus.

often times an antivirus program can just quarentine and delete it. pinkpearl has the right idea though...you gotta identify it first.

no, actually you dont have to identify it, and you dont have to re format your disk either. that is noe way. but you can just make a back up of your hard drive (there are many ways) then just go into BIOS and wipe your hard hard drive without re formatting it, this works with the most common which owuld be NTFS.

Some good info here: http://www.komando.com/

First off, know it may not just be a virus. Many people try and combined viruses with spyware, so they steal all your passwords and or credit/card information, and meanwhile try and damage or completely destroy your whole computer so you don't have time to stop it, and you are distracted. Do not enter any passwords, credit card information, etc while you have it. And no the little *'s that hide your password don't prevent spyware from seeing it.
To stop it, get bullguard free trial (bullguard.com). It's mainly an antivirus, but it does remove some spyware. Scan it, turn off your computer and turn it back on. Scan again. Continue this until no infections are found. Then download adaware free edition (adaware.com or lavasoft.com) which is only a spyware scanner and run that twice. It will always show some minor infections though so don't worry if it never goes to 0 infections. If the infections found on the second scan are only tracking cookies or mru lists, or are classified as minor by adaware, then your good as far as getting rid of spyware.
After you've done all that, you can take some extra precautions by buying bullguard to get advantage of its firewall, and antivirus. Keep in mind though, firewalls help keep your computer safe, but no firewall can fully protect it. Scan your computer every other night with adaware (which is free) and bullguard.
The best way to stay uninfected however is to download what: mywot.com It is a website reputation system that works based on user reputations. If a user gets a virus from a website, they rate it as unsafe.

If you have no antivirus program however, buy one. Bullguard I'd reccomend, but if it's out of your budget, you may get another one. Just be sure to stay away from norton and mcafee. They're popular because most people know little about security.

 
HouseCall is a free online virus scanner offered by Trend Micro, which checks whether a computer has been infected by viruses, spyware, or other malware.

http://housecall.trendmicro.com/

 
After scanning your computer with HouseCall and if you don't have an Anti-Virus program on your computer, consider getting AVG. It has a FREE edition for non-commercial use. I've used it for years and am well satisfied.

http://free.grisoft.com/ww.download-avg-anti-virus-free-edition

CastleCops.com is a forum filled with expert volunteers that will help you clean out malware infections:
http://www.castlecops.com/t102301-Hijackthis_Guidelines_Read_Before_Posting.html

Note the Malware Removal Prevention link, which gives you some basic instructions that should help you clean out many infections without further assistance.