hello friends, firstly, let me say that i am using my laptop, it has avast anti virus programme, this morning i tried to download a file from the website of a friend of mine, the laptop said "cannot install this folder as it does not have a digital signature" it then instructed me to restart my computer and it carried out a scan of my computer, it took about fifteen minutes, it then restarted but has said nothing about a virus, could i have a virus??? any help would be most gratefully accepted, travel safely, joe.