While surfing the net, a threat pop-up came up in size 60 font covering the whole screen. Saying that I have crashed and that my video and sound will not work until I upgrade the media codec. I have tried many adware and malware remover programs. I have AVG antivirus, superantispayware, spybot, spyware doctor, Malwarebutes.

I do not have sound and cannot get video. Can anyone help me.

Do you remember or have the exact message that came up?

And this all worked before this happened?

Have you restarted the computer since?

After restarting if you do so, check below

Check you startup items for anything that may seem unfamiliar, if not sure, you can Google or post startup items here.

Start, run, type msconfig - hit enter
Go to startup tab and go down list and as mentioned, look for items not sure about.