I need free antivirus kaspersky software, so how i will download?

Yes I have used it for years. I also recommend the Kaspersky Rescue Disc.

Download Kaspersky Rescue Disk 10

I found McAfee A little bit of a CPU hog.

I use ZoneAlarm Firewall and Avast for Internet Security.
The combination works out very good.

You need to contact the software company to purchase a key or to get your key replaced.
Nobody here can legally give you a key for any software.

use kaspersky antivirus
go to www.kaspersky.com from your mobile and download the software

Select the operating system you are using from the tabs located in the center top area. The default tab selected is "Windows. " The other tabs are "Mac," "Mobile" or "Webware."
Click on the "Security Software" link found on the left side of the page under "Windows (Mac, Mobile or Webware) Software." This opens a webpage with all of the obtainable security applications. Click on the "Antivirus" link located on the top left to view all of the antivirus programs.
Find free antivirus programs and narrow your selections further. On the left side under "License type," choose "Free" to open a page with only free licensed software. Divide the antivirus programs by your specific Windows version. Click on your exact Windows edition you have under the "by Operating system" categories listed on the left.
Sort the antivirus programs shown. Use the drop-down arrow next to "Sort by:" to change the way the free antivirus programs are listed. The default setting is "Downloads last week," but this can be changed to "Date Added," "Product Name," Editors' Rating," "User Rating" or "Total Download." Change the amount of results shown per page from 10 to either 20 or 30, if desired.
Review the antivirus programs. The ones shown first by default are the Sponsored programs followed by the Editor and User rated antivirus programs. Each one can be reviewed by clicking on the name, which is a link. This opens a page with details about this specific antivirus program. Read over several different ones to find one that is suitable.
Download the free antivirus program. Click on the "Download Now" link or the green button to begin download. Click on "Run" to download and run the antivirus program setup. This will only take a moment. Follow the directions provided to download and install your free antivirus program.

Hello there:
The 2 best available free antivirus download
1. AVG ANTIVIRUS

download AVG on someone elses computer, put it on a disk. uninstall your old antivirus and install AVG. AVG is free and very good. (google AVG).
If your computer is not online, you are not exposed to much malicious software. I certainly thing restoring your computer will do nothing to reactivate your old antivirus.

iam Suggesting Kaspersky® Internet Security 7.0

Antivirus Software: Free 30-Day Trials
http://www.kaspersky.com/downloads