There is any free antivirus software? in my system many virus infect my data?

Go to www.grisoft.com and download AVG Free.

Also www.CyberDefender.com and download Free 2.0

Also www.lavasoft.com and download Ad-Aware.

All of the above are free. The only one you should have on start up menu and running in background is CyberDefender. Run the other two manually every few days.

Also, better to run these in Safe Mode - tap F8 as booting up and choose Safe Mode w/Networking.

Good luck

There is any free antivirus software? in my system many virus infect my data?house call

usually your service provider provides one like Verizon. but you do need to make sure it is turned on.

There is any free antivirus software? in my system many virus infect my data?matchless

Download the free version of AVG anti-virus at the below link. Install it, have it update itself, and then run a complete check of your system. Good luck.
Avg antivirus by grisoft.co has a free version and it's quite safe.

It has helpd meon many occasions
windows live one care is free for 90 days ans i a antiviral program an so is avast it expires in 45 days both free for a trial period
All the following programs are FREE.

They offer Full Time (Active) Virus Protection

If you do not have active virus protection, install only one. All are excellent.