I have download anti virus by Internet,how can I know its work properly?

Just tap your ruby red slippers together and say... there's no place like home, there's no place like home.

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I have download anti virus by Internet,how can I know its work properly?systemworks

I think MISCR is working for it....

I have download anti virus by Internet,how can I know its work properly?windows

Keep it updated. If free, hope for the Best. If Purchased, consult with your antivirus Company Technical Help because you can't be 100% sure on Internet for anything.
U can't really check its working properly or not, but if u really need to check, try downloading a virus (But don't run the virus file, coz it may cause problem) from the internet and save them to your hard disk.

(My repository of virus is in my Bulk folder of my Yahoo Mail, Usually mails filtered to Bulk folder contains a Virus attachement).

I can't guarantee the safety of ur system while doing this, but u can try if u REALLY want to try, AT UR OWN RISK.

Good Luck

And as the person stated above, EICAR can be used to check your anti-virus's ability. But do it on your own risk, and read those instructions in EICAR usage, Very Carefully.
u should install 1st %26 then run daily, if u do that and yr machine is not havoing preoblem means it is working fine.
I highly recommend you purchase antivirus/firewall suite fro a reliable vendor like mcafee. Once the software is installed, make sure you go into the preferences and configure it properly and ensure that it is automatically downloading updates.

You can download an EICAR file to test your antivirus. (google it). It's a file that contains a faked virus signature and your antivirus should alert you if it's properly working.

If you do not have software from a reliable vendor there is no way to tell it's working properly until it's too late.

good luck.