My PC can't go at 20 Mbps

[#1]

HPsause,
I will try running it Malwarebytes in safe mode and will remove and reinstall Avast.
If that fails a friend who knows more than me visiting in the new year.
Thanks,
Wuz

[#2]

I would remove Avast and install something like Microsoft Security Essentials, but only after a thorough malware scan.
If Avast is compromised/corrupt (though other AV products are much worse in this regard IMHO) the cause may be carried over into a reinstall.

[#3]

HPsause,
I ran Malwarebytes under safe mode with networking. Nothing found. I uninstalled Avast and reinstalled. it but it made no difference.
As there was no difference I will try replacing with MSE and see if that helps. I will do it later as I better go out and do the Xmas shopping.
Wuz

[#4]

It could be anything, you'll need an expert to investigate hands-on. Just that those are the most common in my experience.