When we remove a virus from your computer we install "Microsoft Security Essentials" this is an antivirus programme designed by microsoft to protect it's own operating system. This programme is completely free of charge.
We set the update and scan schedule for daily at 7pm, you can change the schedule to suite your requirements but we must stress that to protect your computer you should update and scan your computer regularly.
IMPORTANT
It is very likely that you will get a phone call from someone claiming to be from Microsoft or some other support agency saying that your computer is infected and they will fix it for you, they will ask you to visit their website and will then take control of your computer and demand money to fix it they will want your card details etc.
HANG UP IMMEDIATELY THIS IS A WELL DOCUMENTED SCAM.